Why is April 1 very tiring?

Because you're exhausted after a thirty-one day March.

Getting ready for D-day

D-day will be on Monday. That's when I will have to endure the double-whammy of two midterms - Stratigraphy and Cell Biology. Suffice to say, I'll spend the rest of the weekend buried.

Cheerio, and wish me luck!

Weird quote for today

I dug this one up in a creationist publication.

All flesh is not the same flesh, but there is one kind of flesh of men, another flesh of beasts, another of fish, and another of birds. (1 Corinthians 15:39)

For many years this statement was attacked by unbelievers as being scientifically erroneous. Under the impression that all flesh is made up of protoplasm, the critics were convinced that the Bible was wrong. No distinction could possibly be made, they said, between different kinds of flesh. Today, however, men of science are well aware of the cytoplasm and nuclei of cells, by which four kinds of flesh can be distinguished. Paul, therefore, was perfectly correct in his statement.

[Emphasis mine].

I'm at a loss for words. The original quote from the Bible is poetic, rhetoric, blameless, and entirely unscientific. From that, instead of perhaps discussing genetic differences between fish, birds, and mammals, the text segues into a discussion on protoplasm!

Flesh is not made of protoplasm; cells are stuffed with cytoplasm, with organelles floating around in there. I haven't the foggiest idea where the four kinds of flesh can be distinguished in a cell. Is this an oblique reference to chromosomes? Do they mean actin, microtubules, intermediate filaments, and... never mind. What, exactly, do they mean by flesh?

I'm taking Cell Biology this semester, and seems like our teachers have been holding evidence from us. Either that, or someone's fibbing.

The fine art of Benjamin Waterhouse Hawkins

Nemo Ramjet has posted photos of Benjamin Waterhouse Hawkins' illustrations, as seen in the Natural History Museum of London. They're gorgeously dated, with massive, bloated, pinheaded animals sprawling langourously over the landscape. I won't spoil them for you, but since it pertains to one of my previous posts, I give you:


B. W. Hawkins' Deinotherium. Note the desmostylian shape and proportions. With that view of the animal, one can see why it was though to drag itself on its tusks.

Go now and read Nemo's post!

Tuzoia: beyond the tale of a tail

It's known enough that the stupendous shrimp Anomalocaris was reconstructed from various different, previously-known animals, which proved to be all pieces of the same animal. The mouth appendage was initially described as Anomalocaris, the mouth was named Peytoia, and the body was dubbed Laggania. And in 1928, the Anomalocaris claw became the tail of a crustacean called Tuzoia. Suffice to say that Anomalocaris went on to fame and fortune, a starring role in Walking with Monsters, and the prospect of a life in deckchairs and Ray-Bans.


Less well-known is Tuzoia. Initially described by Walcott in 1912, it is a common fossil in the Burgess Shale. It was highly dispersed during its existence, and was present in Laurentia, China, and Bohemia. Many of its older reconstructions show it with the Anomalocaris-claw tail, but it is a sufficiently fascinating animal on its own.

Tuzoia was an arthropod, perhaps a crustacean, but its appearance was more like a bivalve. However, this is not a unique design; ostracods, for instance, feature a similar body-enclosed-in-a-bivalved-shell morphology. The shell of Tuzoia, like the shell of some ostracods, had a reticulated pattern on the surface that strengthened it while reducing its weight (Vannier et al., 2007). The size of Tuzoia alone put it in a class of its own - at 18 cm in length, it was far bigger than any comparable modern crustacean.

Photo of a Burgess Shale Tuzoia, (note the two valves) from here.


Most of our modern knowledge of Tuzoia can be drawn from Vannier et al. (2007), which reappraised the genus in the light of old and new fossil discoveries. Among the findings was the soft anatomy of the animal, including large, stalked eyes and filamentous antennae. The eyes suggest that Tuzoia had good vision, possibly in three dimensions. Other appendages remain unknown, and they may have been entirely hidden by the shell.

The shell, which was given much attention (see pic), was shown to be sturdy and well-armed with spines. It was nonmineralized and light, affording protection with minimum weight, allowing Tuzoia to float around like an arthropodous clam.

The shell's structure, the large eyes, the global distribution, and the absence of preserved appendages led the authors to the conclusion that Tuzoia was a free-swimming organism like the presumedly pelagic Isoxys and Zhenghecaris.

Diagram showing the external morphology of Tuzoia, from Vannier et al. (2007).


When Tuzoia was first discovered, it was assumed to be a phyllocarid, like the one in the adjacent picture (pic of the phyllocarid Paranebalia longipes from the reports of the Challenger expedition, taken from here). However, like much of the Burgess Shale animals, its relationships are nebulous at best, and Vannier et al. (2007) note its class as uncertain; in fact, there is no direct support for placing it in Phyllocarida, or even Crustacea! Otherwise, it belongs to Order Tuzoida and Family Tuzoiidae. Isoxys and thylacocephalans are posited as possible close relatives. The Tuzoida also accomodates, on occasion, Proboscicaris and Hurdia.

The number of species in the genus was heavily pruned by Vannier et al. (2007), and reduced from 23 to 7. The type species remains Tuzoia retifera.

A final conclusion in the paper notes that the Cambrian water column was home to large arthropods, namely Tuzoia and Isoxys. Their presence "has important implications for the structure and function of the pelagic food chain". Just how an 18-cm arthroclam would affect pelagic ecosystems is anybody's guess.

References

Vannier, J.; Caron, J. B.; Yuan, J. L.; Briggs, D. E. G.; Collins, D.; Zhao, Y. L.; and Zhu, M. Y. (2007) Tuzoia: Morphology and Lifestyle of a Large Bivalved Arthropod of the Cambrian Seas. Journal of Paleontology, 81(3), pp. 445–471

Apathy rules

One of the things that really irks me (and that's saying a lot) is the rampant apathy present here in the students at AUB, especially at the Biology department. I write from experience, and if students aren't like that in other departments, well, I haven't been there.

There are a lot of good students, goodness knows, it's not that. But why can't anyone be moved to do anything? Why does everyone refuse to do anything that isn't directly related to their grades? Perhaps it's the brutal studying requirements. Or maybe it's the massive jungles of red tape that turn people off.

Let me give an example - in fact, the main reason for today's rant. The AUB Biology department once had, in its distant, foggy past, a Biology students newsletter. It was big, printed in color, and attractive, with articles on stuff like flamingos, mummies, and medicine. It also got discontinued, which should have been my hint to stop while I was ahead. But no, part of my projects for the academic year of 2006-2007 was the revival of said magazine. I had it all ready. I had articles on student events, Lebanese cuisine, RNA, the benefits of hugging, and Toxoplasma gondii. I had the layout, the colors, and the pictures. I even had the title - Transcriptase*. There was supposed to have been funding, sponsorship, etc. What happened? Nothing. Nada. Zip. Nul points all round. Part of it was funding issues, and the other was lack of interest. Nobody wanted to write for something whose existence wasn't guaranteed, despite the fact that its existence would be guaranteed if they wrote for it.

*In my defence, it wasn't my idea. I wanted something short and snappy, like The Germ. Really.

This year, 2007-2008, was my second and last bid for the magazine. A pseudo-committee was formed, and another guy came up with a layout and setup that was, yes, better than my original. And what happened? Again, nothing whatsoever. I should have known the project was doomed, all the hints were there. One of my associates said that he didn't mind the quality of the final product, since no-one would read it anyway. It was that last sentence of his that kept me awake at night.

Is this what we've come to? There are people out there that would sell their soul for five more points on the MCAT, or would bribe their medical interviewers to within an inch of their lives. They also don't give a damn about anything that isn't directly related to med school*, let alone something as silly as a biology magazine. They will engage in the most frivolous of activities, and they won't find time for a little extracurricular research that won't get them grades.

*This isn't a rant against med students, but the overwhelming majority of Biology students here are premed.

My conscience is clear. I tried, I failed. At least blogging is another outlet.

Take-home message: students these days are completely apathetic. Good luck getting them to do anything.

Teleoceras, dachshund of the rhino world

Teleoceras has several claims to fame. For a start, it's the best-known, most common North American rhinoceros (Prothero, 1998). Another distinction is its shape - four ridiculously short legs supporting an elongated, barrel-shaped body. While comparisons with dachshunds may be in order, the best modern parallel for Teleoceras is actually the hippopotamus. As will be explained, Teleoceras is the rhinoceros family's answer to the hippo, in the same way that indricotheres emulate giraffes.

Teleoceras, named by John Bell Hatcher in 1894, is a rhinocerotid known from the Miocene to Pliocene of North America. It is distributed over a reasonably large area, and was surprisingly abundant - in the Ashfall fossil beds, for instance, it is the most common mammal species. Not only have many specimens been found, but they include a wide range of individuals, including fetal rhinos and suckling juveniles! Some eight species have been described, including at least one dwarf species ( T. meridianum). The type species is T. major.

Picture by Heinrich Harder, from earlyimage.

With its short legs and barrel-body, Teleoceras would have been slow and clumsy on land. It was described as amphibious early on in its history of discovery, and, as evident in the Harder and Knight paintings, was commonly shows feeding on plants at the water's edge. However, Teleoceras lacked the raised eyes and nostrils found in hippos, and as such was probably less aquatic (Mead, 2000).


Osborn (1898) summarized Teleoceras as "a brachycephalic, extremely short-limbed rhinoceros, partly aquatic in its habits, with a
very large brain and no diploë of the skull". A more complete characterization is given in Prothero (1998). Apart from its truncated looks, Teleoceras also had well-developed hypsodont teeth better-suited for grinding gritty material rather than soft aquatic plants; it most likely fed nocturnally on land like hippos. A single, stubby nose horn is present (further adding to Teleoceras' abbreviated appearance), but the sharp, developed incisors provided a far more fearsome weapon. Incidentally, tusks are a primitive form of defence in rhinos. They are present (and are the primary defensive weapon) in Indian and Javan rhino (Rhinoceros) and are lost in more advanced extant rhinos (Diceros and Ceratotherium), which developed bigger horns.

Skeleton pic from Osborn (1898).


A good amount of information has accumulated on the paleobiology and life habits of Teleoceras. The large numbers of Teleoceras fossils discovered point to it being common (or, at least it was common in areas conducive to fossilization) and lived in herds. While it was always believed to be amphibious, its high-crowned teeth were indicative of a terrestrial-plant feeder; the discovery of fossilized siliceous grasses in some specimens proved that Teleoceras, like hippos, left the water to graze on land (Voorhies and Thomasson, 1979). Sexual dimorphism in Teleoceras was observed from the start (Osborn, 1898) and was given full attention by Mead (2000). The remains of Teleoceras hint at females and immature males being more common than adult males, and the social structure has been suggested to be polygynous, with a high mortality rate of adult males - caused by other males (Mihlbachler, 2003).

Picture by Charles Knight, from here.

Teleoceras was a suprisingly successful attempt by the rhinos to colonize waterways and marshland. Along with the browsing rhino Aphelops, it made it into the early Pliocene, only to be stymied into extinction by changes in flora and climate caused by the Messinian salinity crisis (Prothero, 1998).


References

Mead, A. J. (2000) Sexual dimorphism and paleoecology in Teleoceras, a North American Miocene rhinoceros . Paleobiology; v. 26; no. 4; p. 689-706

Mihlbachler, M. C. (2003) Demography of late Miocene rhinoceroses (Teleoceras proterum and Aphelops malacorhinus) from Florida: linking mortality and sociality in fossil assemblages. Paleobiology, 29(3), pp. 412–428

Osborn, H. F. (1898) A Complete Skeleton of Teleoceras the True Rhinoceros from the Upper Miocene of Kansas. Science, New Series, Vol. 7, No. 173, pp. 554-557.

Prothero, Donald R. in Janis, Christine M.; Scott, Kathleen M.; and Jacobs, Louis L. (1998) Evolution of Tertiary Mammals of North America, Vol. 1. Cambridge University Press

Voorhies, M. R.; and Thomasson, J. R. (1979) Fossil Grass Anthoecia Within Miocene Rhinoceros Skeletons: Diet in an Extinct Species. Science, New Series, Vol. 206, No. 4416, pp. 331-333.

The Boneyard XVI...

... is right here, at The Dragon's Tales.

Respect!

Heatwave!

Er, yeah, like the title says. Today's the hottest day we've had in 2008 (yet), with the thermometer hitting 34 degrees C (Yahoo Weather gives 27 degrees, but you heard the truth here. First). And in the middle of March, too.

Male chauvinist minnows form an all-male pure species

By now, it's common knowledge that some species exist only as females. Reproducing by parthenogenesis, the females give rise to more females, and so maintain an all-female population. A species consisting entirely of males, on the other hand, seems self-defeating. And yet there is at least one fish that does just that, further messing up our definitions of species.


The genus Squalius includes a score of freshwater cyprinids, loosely termed "minnows" (not to be confused with, say, the Eurasian minnow Phoxinus phoxinus). These fish are small and otherwise unremarkable to the casual observer, and are of no real interest to anglers.

The adjacent picture shows Squalius carolitertii, from here.

Squalius alburnoides, however, is a special case. Known as the Iberian minnow, it is relatively common on the Iberian peninsula, and has something very odd going for it. The actual, pure, diploid form of Squalius alburnoides is entirely male, with no females. How on earth did that happen?

In fact, S. alburnoides forms a complex, consisting of hybrid and pure forms which are all labeled S. alburnoides. Whereas the hybrid forms include males and females, the nonhybrid forms are all males. These males "essentially represent a stable all-male lineage nested within an almost all-female lineage" (Alves et al., 2002).

The diploid all-male minnows reproduce with triploid, hybrid females, which make haploid eggs whose single chromosome set is identical to that of the males. With such matings producing only males, the male line is maintained, while the hybrid females produce more hybrids by reproducing with hybrid males.

The evolutionary origins of this complex remain unclear, but the adjacent diagram (taken from Alves et al., 2002) shows a speculated route. Diploid hybrids originate from a cross between the related Squalius pyrenaicus and an ancestor genetically identical to the male lineage of S. alburnoides. Another mating with a pure male gives a triploid hybrid, and that hybrid gives nonhybrid male S. alburnoides upon mating with nonhybrid males. Hybrid matings produce more hybrids. In this way, "the all-male lineage allowed preservation of the ancestral paternal nuclear genome" (Alves et al., 2002).

Given the unusual mechanisms at work in this complex, a reasonable number of papers have been produced on its subject. For instance, Cunha et al. (2004) calculated that the hybridization events started in the late Pliocene, and discussed the evolution of the complex. Robal et al. (2006), based on molecular evidence, posited an intergeneric origin for S. alburnoides, placing it closer to Anaecypris hispanica as a hybrid of A. hispanica and S. pyrenaicus.

Whatever the origin of the all-male line of S. alburnoides, its existence is yet another blow to the idea of "species" as a fixed, sacrosanct entity.


References

Alves, M. J.; Collares-Pereira, M. J.; Dowling, T. E.; and Coelho, M. M. (2002) The genetics of maintenance of an all-male lineage in the Squalius albuvnoides complex. Journal of Fish Biology 60 (3) , 649–662

Cunha, C.; Coelho, M. M.; Carmona, J. A.; and Doadrio, I. (2004) Phylogeographical insights into the origins of the Squalius alburnoides complex via multiple hybridization events. Molecular Ecology 13 (9) , 2807–2817

Robalo, J. I.; Sousa Santos, C.; Levy, A.; and Almada, V. C. (2006) Molecular insights on the taxonomic position of the paternal ancestor of the Squalius alburnoides hybridogenetic complex. Molecular Phylogenetics and Evolution, Volume 39, Issue 1, April 2006, Pages 276-281

A sure sign of impending apocalypse

One word: LOLsauropods.

Wait, is that two words?

Photo du jour: Lychnophaes globosus

Working with insect collections can be seriously interesting fun. After going through several boxes of chrysomelids, I found a few gems, such as Lychnophaes globosus here.


Honestly, with that iridescent sheen, it looks like a fugitive from Halo 3.

Note also the atrocious condition of the pin. This is from a collection almost as old as AUB itself, and it's being renovated as we speak.

This is how trading cards should be

This trading-card making site sure is fun. Imagine getting kids to swap these beauts around - and think of what they'd do for science education...


A pity there's a limit to how much text you can cram into one of these things. The longer names just won't fit up at the top.

Like I said, the lecture...

... was awesome. It was a general, layman's introduction to paleontology, sweeping through 4.5 billion years' worth of evolution, as well as covering the quirks of life as a paleontologist. There was a sizeable audience (considering the subject matter), and there were questions aplenty at the end of the lecture. I'm not going to say that I'd have liked it to be more technical, mainly because it was never meant to be technical.

Oh, and there were deinotheres. That's also awesome.

The deinotheriids - giant tapir-elephants

Consider the loss and otherwise total destruction of Shakespeare's works. All of them except two or three - say, The Winter's Tale and The Two Gentlemen of Verona, certainly not the greatest or most culturally significant. Quite a blow for the world of literature, I'm sure you'll agree.

The proboscideans have suffered a similar fate. The African bush elephant, the African forest elephant, and the Asian elephant are the last remnants of a large and diverse group that once spanned several continents. Order Proboscidea has produced many spectacular creatures - moeritheres, shovel-tuskers, mammoths, mastodonts... and deinotheres, which will be the subject of this post.


Family Deinotheriidae diverged relatively early from the rest of the Proboscidea. They belong to the Deinotheroidea, a suborder separate from the more familiar Elephantoidea and outside the Elephantiformes. Shoshani and Tassy (2004) place the Deinotheroidea, Barytheriidae, and Numidotheriidae within the Plesielephantiformes, a sister-taxon to the Elephantiformes. Some radical classification schemes place them outside the Proboscidea, but this is unlikely.

Deinotheres first appeared in the late Oligocene of Africa, specifically Chilga, Ethiopia (Sanders et al., 2004). From there, they spread into Europe and Asia where they thrived until the mid-Pliocene. The last deinotheres were found in Africa, their land of origin, where they made it to the early Pleistocene and were contemporaries of early hominids.

The deinotheriidae was not a particularly speciose group, but it was reasonably successful during its lifespan. Three deinotheriid genera are known, divided into the Chilgatheriinae (Chilgatherium) and the Deinotheriinae (Prodeinotherium and Deinotherium). The species follow each other temporally and replace the previous species. The late Oligocene Chilgatherium is the earliest known deinothere, described in 2004 on the basis of a few distinctive molars (Sanders et al., 2004); it was around pig to hippo-size. Prodeinotherium appeared later, during the mid-Miocene, and remains have been found in Africa, Europe, and Asia; the animal was about the size of a small elephant. Deinotherium was the last deinotheriid, and the best-known (and certainly the only one that appears in popular-paleontology books). It lived from the mid-Miocene to the Pleistocene in Europe, Asia, and Africa. It was also huge, standing 5m tall and weighing 14 tons, at an estimated maximum, making it one of the largest land mammals ever to exist. Only Indricotherium and the controversial Mammuthus sungari were larger.


The most instantly recognizable feature of deinotheriids are their tusks. The upper tusks are entirely absent, while the lower tusks curve downward in a hooked shape and point to the ground. It is unknown whether or not the earliest deinotheriid had those tusks, but both of the later species had them. Apart from that, deinotheriids had diagnostic molars and relatively low, flattened skulls.

The exact function of the tusks remain unknown. At one point, when Deinotherium was assumed to be amphibious, it was suggested that they were used by the animal to haul itself out of water, like a walrus (Osborn, 1936)! Deinotheriids may have used their tusks to root out tubers, pull down branches, strip bark from trees, or fight other deinotheres, but this remains speculative.

Image of Deinotherium skull and teeth from Wikipedia.


The teeth of deinotheres were best suited to browsing from trees. Harris (1975) compared their feeding to that of tapirs, with similar shearing actions. With their great height, deinotheres could easily have browsed in the branches of trees. They were probably very good at it, too, since the basic deinothere plan did not change throughout their evolution.

The trunk of deinotheres is a different matter entirely. Most artists depict Deinotherium and its relatives as nothing other than overgrown elephants with downward tusks, as evident in the adjacent picture. However, more recent research indicates that something far more bizarre was going on in the deinotheriids...

When Osborn first reconstructed Deinotherium back in 1910, he drew it with a short, flap-like trunk much like a tapir's, but later dropped that reconstruction for no known reason (Markov et al., 2001).

This reconstruction was revived by Markov et al. (2001). From a study of the skull's shape, they deduced that Deinotherium must have had a short, tapir-like snout hanging over its descending lower jaw. A long trunk was not necessary, as a browser standing 5 m high at the shoulder had little need to reach the ground. The tusks remained free for whatever purpose they served, and the nostrils, at the end of the proboscis, could smell and inspect food.

To be sure, it's quite a dramatic suggestion, and, if correct, further demonstrates just how diversified proboscideans were during their long history.

Image by Velizar Simeonovski, from Markov et al. (2001).

While the other two species of deinothere invariably get shortchanged, Deinotherium is fairly common in popular-paleontology books, usually in group pics of elephant evolution. For some reason, three-quarters of Deinotherium pictures show it with its mouth open. Deinotherium also got a role in Walking With Beasts, in which a bull Deinotherium in musth almost steamrollers a young Australopithecus. That's awesome.

All pictures, unless otherwise noted, are from earlyimage.


References

Harris, J.M. (1975) Evolution of feeding mechanisms in the family Deinotheriidae (Mammalia: Proboscidea). Zool. J. Linn. Soc. 56: 331-362

Markov, G. N.; Spassov, N.; and Simeonovski, V. A reconstruction of the facial morphology and feeding behavior of the deinotheres. The World of Elephants, International Congress, Rome 2001

Osborn, H. F. (1936) The Proboscidea.

Sanders, W.J.; Kappelman, J.; and Rasmussen, D. T. (2004) New large-bodied mammals from the late Oligocene site of Chilga, Ethiopia. Acta Palaeontologica Polonica Vol. 49, no.3, pp. 365-392

Shoshani, J. and Tassy, P. (2004) Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior. Quaternary International, Volumes 126-128, 2005, Pages 5-20

Enough crackpot hypotheses to go around

In The Snouters, it was (hilariously) stated that flatworms are mammals with a highly developed nose and a degenerate body.

However, some other hypotheses seem just as silly, and yet they're dead serious. Darren Naish has been covering them in detail for some time now. There's one that says that birds and mammals share a common ancestor, and another that claims that all animals evolved from bipedal, humanoid airheads. Yup, now those are what I'd call fringe hypotheses.

Close Encounters of the Blurred Kind: Scolopendra

Large centipedes of this sort (genus Scolopendra, unidentified species, probably S. cingulata) are quite common, even in populated areas. Every other rock at AUB has a centipede holed up under it, and they can be seen crossing roads, as this one was doing before I unceremoniously helped it across.

Scolopendra are top arthropod predators wherever they are feeding, feeding on anything from small insects to spiders and scorpions. Back at school, some of my classmates had the inspired idea of putting a centipede in a box with a tarantula and leaving them overnight. There wasn't much left of the tarantula by next morning.

Despite the size of the centipedes, bites from Scolopendra species are not life-threatening (which isn't the same as saying they're not painful, though!). They can cause swelling, irritation, and varying degrees of pain. The bite of species here is about as painful as a wasp's sting, but tropical species are much worse. Centipedes are held in great fear by villagers, who make sure to thoroughly burn the unfortunate arthropods and wash anything they touched.

This is going to be awesome

I'm totally going to attend this lecture.



It's tomorrow. And it's going to be awesome.

Happy St. Patrick's Day!

If you celebrate it, of course. It's not a holiday - national, recognized, or widely celebrated - in Lebanon, however.

In the spirit of the occasion, I present a four-leaf clover.



I occasionally find four-leaf clovers in the wild, untamed backwoods lawns of AUB. I heard from at least one person that the species present does not produce four-leafers; I've got the four-leafers to prove him wrong.

Oh, and I eat them after finding them. You can't go wrong with that sort of luck.

UPDATE: it's not a four-leaf clover. Whatever you do, don't trust me with your botany.

Aidohwedo

Note: this is was made for a deviantArt contest. The idea was to create a non-humanoid sentient alien. My submission was here.

***************

Begin transmission

Aidohwedo

Image



The picture above shows a typical aidohwedo specimen, and the faces of four other individuals, to illustrate the species' diversity. The bar of color is the name aidohwedos apply to themselves. Also shown are the aidohwedo home planet and a scale comparison with a human.

Species

Chromoserpens faber
Native name: [Unpronounceable]
Recognized name: Aidohwedo, rainbow serpent
Other names: Rainbow, tailhand, slitherer, snake, worm…

Naming history

The language of aidohwedos is impossible to translate properly. A gathering of the PUNKS (Planetary Union Naming Known Sentients) settled on “aidohwedo” as an official, non-discriminatory name, but the name “rainbow serpent” remains in common usage.

Home planet

Again unpronounceable in the tongues of man, but consensus sets its name to Ophicron I. Earth-type planet with similar chemistry, albeit larger, warmer, and with more oxygen. Second of a series of 5 planets (3 rocky planets and a gas giant, plus an asteroid field and a few dwarf planets) orbiting a double star system.

Biology

Aidohwedos have an extensively metamerized body; that is, it is divided into segments like an earthworm’s. Each segment bears a unique neural ganglion and a heart. The rest of the organs go through the body in much the same way as they do in snakes. The respiratory system opens to the outside by a line of spiracles on either side of the “neck”. The skeleton is jointed, with one skeleton element per segment; it is itself covered with another layer of muscle and skin, such that the divisions are not externally apparent. The tail, which starts after the anus, takes up about a third of the serpent’s length, and ends in a muscular, three-fingered “hand”, the dextrure. The skin has the texture, smoothness, and consistency of rubber.

The head varies in shape, but is generally elongate, with a crest of protofeathers running down it. Two pairs of eyes are present, both with an immense color range: compound eyes and very sensitive complex eyes (the compound eyes are an ancestral characteristic that was never lost in the serpents’ class). There is a small opening for a mouth, which can be closed with a tough flap of skin. The feeding apparatus, comprised of two pairs of stylets, can be extruded or retracted from there. A pair of retractable, three-pronged tentacles, or palps, is present on either side of the head.

The entire body, with the exception of the head, is covered with a complex chromatophore system, and allows an aidohwedo to change color at will. The palette of colors includes millions we can see and many more that we trichromats cannot even imagine. The head, which lacks chromatophores, bears a unique, fixed color and pattern, which is used to identify individuals.

Feeding

To feed, an aidohwedo extends its proboscis and punctures the skin of its food. Through the injection of venom and enzymes and the mechanical action of the stylets, a pocket of tissues is liquefied and can be sucked up by the serpent.

Aidohwedo venom ranks among the most virulent toxins in the known universe. Understandably, other sapients would be reluctant to pick a fight with an aidohwedo, although the aidohwedos themselves consider it poor form to use venom in a brawl.

Reproduction

Aidohwedos are dioecious. Male and female sexes are present. A aidohwedo is born male and matures sexually; then, after a certain point, he becomes female – making the aidohwedos among the few sentient species to go through puberty twice. This system can be found in some Terran animals such as groupers. Aidohwedos can live to an average of 100 years, living half that as a male and the rest as a female. As females are twice the size of males, all large serpents are female, as are all older serpents.

The palps are used by male serpents to inseminate females. The female gonopore, a slit in the neck, becomes active after the second puberty, and is the site of fertilization. After a six-month gestation period (the serpents are ovoviviparous), the female gives birth to one or two young aidohwedos. During their juvenile years, their exoskeleton is apparent and makes them look like large centipedes – aidohwedos react to different cuteness cues than we do. Only after they become mature males does their body become smooth.

Palps remain present even after the aidohwedo has matured into a female, and are used by both sexes as manipulatory organs alongside the dextrure. However, direct palp-to-palp contact is considered erotic, and as such is taboo outside of sexual encounters. Aidohwedos were reportedly shocked upon first seeing humans shaking hands.

Language

The language of aidohwedos is impossible for humans to understand with advanced visual translation programs and AI. Aidohwedos read color, with nuances, hues, and patterns translating to words and concepts. Although languages vary from nation to nation, the most common language is Basic Chromolalia, “spoken” by most offworld aidohwedos.

An aidohwedo speaks by changing the colors on its body. The color starts behind the head and moves in a wave to the end of the tail as new speech appears at the origin. A talking aidohwedo is a dizzying riot of shifting color, and some humans are known to have seizures looking at aidohwedos. That said, aidohwedos themselves hate human advertising, as the colors used recklessly on Earth as read as screaming gobbledygook.

Aidohwedos are incapable of making sounds, other than a sinister hiss caused as a side effect of forcefully expelling air from their spiracles. They can feel vibrations in the ground, but their language remains visual.

As the head cannot change color, it is essential to identify individuals.

Blind aidohwedos and mutants lacking chromatophores cannot communicate. Conversely, mutants whose head bears chromatophores are highly feared, as they could effectively disguise themselves at will.

Personality

It would be gross oversimplification to pigeonhole aidohwedos into a single personality group. Like humans, they individuals can be intelligent, creative, technically-minded, compassionate, athletic, sadistic, depressed, good salesmen, outstanding pilots, responsible teachers, conscientious sewer inspectors… They can be found doing virtually every job in the galaxy that their anatomy allows.

Nevertheless, aidohwedos have a distinct advantage over other races due to their exceptional color awareness and sharp vision, and excel at functions making use of their sight and hair-trigger reflexes.

History and Culture

The history of the aidohwedos is long and colorful, including a stone age, an age of exploration, an imperial age, and several world wars. To cover it all is beyond the scope of this summary.

Female aidohwedos are the dominant sex, occupying most positions of power, fighting wars, and dominating family groups. Male suffrage movements have done a lot to increase male rights, but they still have some way to go. As a result, males are more likely to leave Ophicron I in search of adventure.

A family is comprised of a female and her offspring. Males remain with their mother until they become females; in the meantime, they are encouraged to fertilize as many (consenting) females as possible while they still can.

Clothing is not worn, as it would prevent communication. Some repressive cultures, however, force males to wear a full-body sheath that stops them from talking. Such behavior is seen as appalling by enlightened aidohwedos, and much has been done to stop it, but old habits die hard. Jewelry is sometimes worn on the head, usually by males.

Ophicron I has turned out many scientists, artists, engineers, medics, and pilots. There are also numerous corporations on Ophicron I that produce fine starships, although they have to be modified depending on the user’s species. The Cyanspot (a shortening of its complete name) is one of the most common fighters in the known universe.

Aidohwedos are generally outgoing and open to integration with other sentient species, but they often suffer at the hands of the arch-xenophobes – the humans.

Text and image taken from Encyclopedia Galactica – Human Edition – English translation, by Sagan Books, used with permission.

End transmission

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Today's photo: Sword-billed Hummingbird

The sword-billed hummingbird Ensifera ensifera, described by Boissoneau in 1840, has the longest bill of any bird in proportion to its body. A fine example of co-evolution gone wild, it pollinates the flower Passiflora mixta, whose corolla is long and fine to deny access to other animals. (Lindbergh and Olesen, 2001).


References

Lindbergh, A. B. and Olesen, J. M. (2001) The fragility of extreme specialization: Passiflora mixta and its pollinating hummingbird Ensifera ensifera. Journal of Tropical Ecology, 17: 323-329 Cambridge University Press

The fearsome, bloodthirsty Megatherium (?)

Take a good, long look at the animal in the adjacent picture. Does it look like a ferocious carnivore to you? Big, yes; clawed, yes; but it's essential a scaled-up terrestrial version of the humble three-toed sloth. It may be able to defend itself ably, but you wouldn't have much trouble convincing a jury of Megatherium's herbivorous tendencies.

In fact, as long as giant ground sloths were known, they were considered plant eaters*. It didn't take long for ground sloths to be stereotyped as lumbering giants with the mental faculties of bowling balls. But a 1997 paper threw a spanner in the works...

*Okay, okay, when Megalonyx was first described, it was assumed to be a big cat. A dietary consensus came later.

Farina and Blanco (1996) pointed out that the arms of Megatherium, had a short olecranon process, an adpatation that maximized its stabbing movements and optimized its arms for speed instead of strength. With this being typical of carnivorous animals, the authors then went on to argue that Megatherium was therefore the largest mammalian carnivore, and specialized in preying on glyptodonts (adjacent picture shows Glyptodon). The reasoning was that Megatherium was strong enough to flip a glyptodont and puncture its soft underbelly, furthermore, its muscular biceps would have allowed it to carry the unfortunate glyptodont away for eating or cacheing.

Which is, of course, a rather radical idea, and open to question. After all, Megatherium's teeth lacked any particular specializations for eating meat, although Bargo (2001) indicated that it was capable of strong, cutting bites. The size of Megatherium also seems like overkill on its prey, and, well, it was as sprightly as a steam locomotive (not that glyptodonts were much faster...) The "killer strike arms" also are not necessarily those of a predator; they could have been an awesome defensive force. Then again, at Megatherium's size, it's hard to imagine what could prey on it (puny sabertooths? Pah!) Traditionally, Megatherium was expected to use its arms to tear down branches and strip bark. As you can see in the picture, Megatherium was a bit of a tree-hugger.

The jury is still out on this one. It remains more likely that Megatherium was a herbivore, but, as my biology teacher used to say, there are no true herbivores or carnivores in nature. Sheep bite off seabird legs. Cats munch on catnip. Giraffes scavenge antelope backbones. In the same way, surely a vegetarian Megatherium would not have passed up a free protein and calcium supplement? That was the view presented in Walking With Beasts, and I daresay their Megatherium was badass.

Pics, as usual, from earlyimage.


References

Bargo, M.S. (2001) The ground sloth Megatherium americanum: Skull shape, bite forces, and diet. Acta Palaeontologica Polonica 46, 2, 173–192

Farina, R. A. and Blanco, R. E. (1996) Megatherium, the stabber. Proceedings of the Royal Society of London 263: 1725–1729

Alas, poor Diatryma...

... I knew him well. There was a time when Diatryma was the scariest thing present in an Eocene landscape; a time when that giant, flightless, hatchet-headed relative of ducks was depicted ripping Hyracotherium (or Eohippus, as it was commonly known then) to shreds. Diatryma was a classic, featured even in rubber figures. And yet, not only has Diatryma ceased to be, but even its diet was reconsidered several times.

When Cope discovered the remains of an Eocene bird in 1876, he named the animal Diatryma gigantea, after its boat-like bill and its perceived large size. Despite the fragmentary nature of the fossil, it was interpreted as a large, predatory bird with a massive carving-knife of a beak. As the first big, carnivorous flightless bird known (Phorusrhacos was unearthed in 1887), it garnered publicity, not to mention notoriety. It wasn't long before Diatryma reached its clichéd depiction - standing bloody-beaked over a dead primitive horse.

The phorusrhacids, although clearly predatory, were of a different build and appearance, and so were not related. However, there was another bird related to Diatryma, but whose parentage took much longer to be determined.

That bird was Gastornis parisiensis, a prehistoric bird found by Gaston Planté (hence the genus name) and named by Hébért in 1855. The skull of Gastornis was not known, and after Lemoine unearthed new remains including a partial skull, he reconstructed Gastornis with a narrow, toothed bill (the influence of Archaeopteryx, Ichthyornis and Hesperornis was clear). This reconstruction (pictured on the right) was not only erroneous, but delayed the recognition of Gastornis as Diatryma's relative (Buffetaut, 1997).

Eventually, further work by Buffetaut reached a consensus view that Diatryma and Gastornis are congeneric, and the mighty Diatryma found itself relegated to the big boneyard in the sky reserved for junior synonyms. Still, Diatryma is used in some publications (e.g. Paul, 2002).

To add insult to injury, Gastornis' diet has been reconsidered several times during its history. The bird has variously been considered as a predator (the original view), a herbivore (the nadir of its career), an omnivore, or a scavenger. Part of the justification for dropping the predator status was the fact that Gastornis was heavily built and unsuited for running (as opposed to the rangy, fleet, and undoubtedly predatory phorusrhacids), and its heavy beak lacked the hook present in carnivorous birds. However, a study by Witmer and Rose (1991) concluded that Gastornis was capable of massive bite force that would be overkill on existing plants, and suggested bonecrushing capabilities. If Gastornis was a predator, it would probably have to ambush its prey, given its morphology. Living in a wetland environment, it could have been an opportunistic, bear-like omnivore; Paul (2002) compares it to shoebill storks and mentions that it could have crushed turtles.

All in all, Gastornis likely did disembowel proto-horses. Diatryma's honor is intact.

Both pics from earlyimage.


References

Buffetaut, E. (1997) L'Oiseau geant Gastornis; interpretation, reconstitution et vulgarisation de fossiles inhabituels dans la France du XIXe siecle. Bulletin de la Société Géologique de France; November 1997; v. 168; no. 6; p. 805-811

Paul, G. S. (2002) Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Johns Hopkins University Press.

Witmer, L. M, and Rose, K. D. (1991) Biomechanics of the Jaw Apparatus of the Gigantic Eocene Bird Diatryma: Implications for Diet and Mode of Life. Paleobiology, 17 (2), pp. 95-120.

Explanations, part II: The World We Live In

Since this blog was created to deal with mainly extinct or speculative animals, The World We Don't Live In seemed to be logical enough as a title. However, it was made as a direct, thinly-veiled reference to the 1955 book The World We Live In. I'll link to its Wikipedia page because, honestly, I wrote practically all of that page.

The World We Live In first came out between 1952 and 1954 as a serial in Life magazine. Written by Lincoln Barnett, it aimed to cover, well, the world we live in. Chapter I covered the origin of the Earth, Chapters II - IV were on the sea, the earth, and the air, Chapters V and VI dealt with prehistory, Chapters VII - XII covered different ecosystems, and Chapter XIII was on the far reaches of space.

By all accounts, the writing in The World We Live In is purpler than the inside of a rainbow. Barnett refers to dinosaurs as being "unperceiving, insensate, brainless brutes"; Tyrannosaurus was a "towering agent of destruction, endowed with gigantic strength and power". It also appears that Life didn't want to lose its readership, and Barnett made sure to include Biblical quotes into the text (most notably a quote from Genesis headlining the chapter on evolution!) By modern standards, the text is hopelessly outdated, though. And yet, it radiates wonder and awe at the sheer marvelousness of the earth and universe. There are a few other books that radiate the same starry-eyed fascination; I could mention Darwin's Origin of Species and Carl Sagan's Cosmos.

The art is lovely, and was (at the time) scientifically irreproachable. Most people remember Rudolf Zallinger's murals of the Age of Reptiles and the Age of Mammals, and Chesley Bonestell's majestic space-scapes. But the other pictures are also exemplary - the panoramas of desert, tundra, rainforest, and other ecosystems; the dramatic illustrations of geological forces at work; the colorful insects of Walter Linsenmaier. The fact that the pictures were printed on such large pages added to the impression they made on readers.

The World We Live In was later published in book form, and then re-adapted into a diluted edition for younger readers (deleting and cropping several pictures in the process - the entire Paleocene landscape and Megatherium were completely lost from the Age of Mammals).

If The World We Live In was to be updated for today, it would require a massive overhaul, and many pictures (not to mention most of the text) would have to be revised. But, in its original form, it introduced many people to the wonders of natural science. I was one of those people, and I named this blog in honor of that book.

Okay, sentimentalist rant over. More paleo-content coming up!

Close Encounters of the Blurred Kind: tortoises

Tortoises aren't very conspicuous animals. They like to hide and dig themselves in places - sometimes, when I released my pet tortoises in the garden, it'd take me till nightfall to find them again. I was certainly quite surprised when I found a tortoise in the AUB, of all places.



Apparently, they were released on campus as part of an experiment, and apparently are doing reasonably well. They're all Mediterranean spur-thighed tortoises Testudo graeca, a quite common species in these parts.



I saved this second tortoise from the attentions of a cat. If there's one animal that's ubiquitous in AUB, it's the domestic cat, in huge populations that lay waste to the surrounding area. Only time will tell if turtle shells are adequate protection from ravenous cats.

Explanations, part I: the animals

I have some 'splainin' to do. Now that a certain number of people (I think) are reading my blog, it's about time I gave a reason for some things on this blog. Yes, they're all personal idiosyncracies, in case you were wondering.


This blog's URL honors the gloriously bizarre Eobasileus cornutus (Cope, 1872), one of the last, largest, and certainly the most derived of the uintatheres. Known from the mid-Eocene, it had no less than six knobby horns on its head, and a pair of tusks protected by "sheath" flanges. Uintatheres died out before the end of the Eocene, and left no descendants; still, it's hard not to like the big lugs. Yes, I do have a thing for Tertiary ungulates with more than one pair of horns.


My profile picture represents Sphenacodon ferocior (Romer, 1937), a large pelycosaur from the Permian. Unlike the better-known Dimetrodon, Sphenacodon lacked the tall neural spines, and at best probably had a low ridge down its back. The picture is by Rudolf Zallinger, and, coupled with the Charles Knight Eobasileus, makes a good enough contrast. So, these two animals are mascots of sorts.

The distinction of Lizard Wizard was bestowed unto me by the creative team behind the Speculative Dinosaur Project - something for which I am very grateful.

Finally, as for the title of The World We Don't Live In... well, that'll have to wait for a future post. There's a lot I have to say about the subject.

I don't want to know how he got there

No, I really don't want to know how he got there. And I'm glad I wasn't around when he did.

Not a sight for sensitive pterosaur researchers

Remember David Peters' incongruous Jeholopterus? Well, Nemo Ramjet now gives us a rendition of David Peters' Pteranodon, in full, terrifying color.

Okay, it's every shade of wrong, but it looks awesome. Great job as usual, Nemo!

How Compsognathus almost got flippers

Here's a quick paleontological anecdote to mention at cocktail parties: at one point in its history, little Compsognathus got described as a flippered aquatic lizard. Yes, we're talking about Compsognathus, the same animal now acknowledged as being feathered, birdlike, and generally terrestrial. How on earth did that happen? As you begin to gather a (hopefully interested) audience, start with the details.


It all started with the 1972 discovery of a new Compsognathus specimen, MNHN CNJ 79, in Canjuers, near Nice. A substantially larger animal than the pusillanimous Solnhofen specimen, it was described as a new species by Bidar, who named it Compsognathus corallestris. Here's a picture of the skeleton in question (image from Wikipedia's Compsognathus page).

While the holotype of Compsognathus (BSP AS I 563, from Solnhofen) had a fragmentary manus and so was interpreted as being two-fingered, this new specimen was considerably better-preserved, and a supposed fin-membrane led Bidar to a strange conclusion: Compsognathus had flippers. I wasn't able to get my hands on Bidar, Demay, and Tomel (1972), but the general gist of it was that Compsognathus used its flippered forelimbs to get from one island to another, and to escape predators. This remarkable idea was developed into some illustrations, including an amusing image by John Sibbick (Norman, 1985).

Regardless, Bidar's conclusions were not watertight. John Ostrom, in 1978, was the first to denounce the existence of flippers and the species status of C. corallestris. The exhaustive studies of Michard (1991) and Peyer (2003 and 2006) further established that not only was the evidence for flippers lacking, but also that that Compsognathus corallestris was the same species as Compsognathus longipes. In all likelihood, the Solnhofen specimen was not yet fully grown. Finally, the fin-like structures on the Canjuers specimen turned out to be nothing more than sedimentary disturbances (Peyer, 2006).

Other examples of the tribulations of Compsognathus include
a) getting pictured for decades with only two fingers, and without feathers; or
b) the fact that, despite Huxley's endorsement of the link between Compsognathus and Archaeopteryx, the dino-bird connection took flight much later.
These are all other stories, though - all I wanted to talk about was the purported presence of fins on a bleeding-obvious terrestrial animal.

References

Michard, J. G. 1991. Description du Compsognathus (Saurischia, Theropoda) de Canjuers (Jurassique supérieur du Sud-Est de la France). Position phylogénétique, relation avec Archaeopteryx et implications sur l'origine théropodienne des oiseaux. Université de Paris.

Norman, D. 1985. The Illustrated Encyclopedia of Dinosaurs. Salamander Books, London

Peyer, K. 2003. A complete redescription of the French Compsognathus with special consideration of the anatomy of the hand. Journal of Vertebrate Paleontology, 23 (3, supplement), p. 87

Peyer, K. 2006. A Reconsideration Of Compsognathus From The Upper Tithonian Of Canjuers, Southeastern France. Journal of Vertebrate Paleontology 26: 879–896.

The Boneyard XV...

... is over at Laelaps. Go and pay a visit!

The Protoceratidae - slingshots and beanies

Here’s a little thought-experiment to try. Imagine a deer, or deer-like animal. Now give it fang-like tusks, like those of a muntjac, and prehensile lips. Now give it a pair of horns on its head. Give it another pair of horns on the tip of its nose. You can be creative with the horns if you want – merge them together, shape them into V or Y figures, or add an extra pair near the first, if you see fit. If you can imagine such an animal, you’ve got a pretty good idea of what a protoceratid looks like.

The Protoceratidae are a fascinating and unusual family of artiodactyl ungulates, noted for their baroque headgear. Unique to North America, they appeared in the mid-Eocene and disappeared by the start of the Pliocene, and were widespread, if uncommon, throughout their existence. Thirteen genera have been described to date.

As mentioned earlier, many protoceratids evolved bizarre horns. Some species had up to six horns, in a manner reminiscent of dinocerates. At least one species seemed to be wearing a propeller beanie. The later synthetoceratines carried the trend to the extreme, with a pair of horns on top of their head and another, often fused pair on the tip of their nose developing into an outlandish slingshot.


While the odd horns are a dead give-away for a protoceratid, the earlier species lacked horns altogether, so other characters are used for identification. Generally, the diagnosis for protoceratids is a short coronoid process on the mandible, a concave proximal side of sustentacular facet of astragalus, and strong upper molar lingual cingula (Prothero, 1998). The absence of a third metacarpal (the cannon bone) is also noteworthy. Many species also had enlarged canines much like those found in muntjacs, and advanced species lost their incisors entirely.

Painting of Protoceras by Heinrich Harder, from here.

Phylogeny and relationships

The phylogeny of protoceratids has been the subject of some dispute. When O. C. Marsh discovered Protoceras, the first known species, he assigned it to the giraffes; and, since then, protoceratids have been variously allied with giraffes, ruminants, and camels. The two best-supported hypotheses are that protoceratids are either a) the sister-group of tylopods or b) the sister-group of ruminants (Norris, 2000). It seems most likely that protoceratids are tylopods, whose closest relatives are the camelids.

Within Protoceratidae itself, subfamily “Protoceratinae” is used as a wastebasket for upper-level taxa. The subfamily Synthetoceratinae, within Protoceratinae, includes the later species with Y-shaped rostral horns, and it is further subdivided into the Kyptoceratini (with the rostral horn fused at the base, as in Syndyoceras) and the Synthetoceratini (with a long rostral horn, as in Synthetoceras).


A quick tour of the Protoceratidae

Leptotragulus, Leptoreodon, Poabromylus, Toromeryx, Heteromeryx, and Pseudoprotoceras are all basal protoceratids, without horns. A study of Leptotragulus, the earliest protoceratid, concluded that it already had many protoceratid specializations, and had evolved a strong skull and neck to support head-butting and other agonistic behavior (Norris, 2000). The known skull of Heteromeryx is hornless, but it might be a female specimen without horns. Pseudoprotoceras is also hornless, but, again, it has been suggested that the known specimens were all females; it also may be a "protoceratine".

Protoceras skeleton from here.

The “Protoceratinae” include the more famous horned species. Strong sexual dimorphism is known in Protoceras, whose males had no less than six horns – a pair on the maxilla, a pair on the orbit, and a pair on the parietals. Female Protoceras, on the other hand, retained only one pair of horns. The Protoceras type specimen was female, and as such caused some taxonomic confusion (Prothero, 1998). The closest genus to Protoceras is the equally six-horned Paratoceras, whose occipital horns fused at the base and spread out laterally into two flattened horns, likened to a propeller beanie.

All the remaining protoceratines are sorted into the Synthetoceratina, which itself divides into the tribes Kyptoceratini and Synthetoceratini. The Kyptoceratini includes two species. The easily-recognizable Syndyoceras had curving frontal horns and V-shaped rostral horns emerging directly above their base. Kyptoceras was the last known protoceratid, surviving into the Pliocene. The horns of Kyptoceras were similar to those of Syndyoceras, but both pairs were forward-tilting.


The Synthetoceratini includes most of the last and largest protoceratids. All three species had frontal horns and “slingshot” rostral horns on the end of a long projection. Lambdoceras, Prosynthetoceras, and Synthetoceras all followed this arrangement. Synthetoceras was the largest protoceratid, one of the best-known, and the latest-surviving species known until the discovery of Kyptoceras in 1981. Described at one point as a “near-unicorn” (Barnett, 1955), it is possibly the weirdest protoceratid, and often serves as a poster boy for the rest of the family.

Picture shows Syndyoceras (bottom) and Synthetoceras (top).

Paleobiology

With short limbs, protoceratids were probably poor runners, better-adapted for life in forests and woodland. The lack of incisors and the retracted nasals suggest the presence of a prehensile lip to pluck off plant matter. In all, they seem to have been rather like the extant moose. A study of the premaxilla showed that Synthetoceras was a grazer at ground-level (Solounias and Moelleken, 1993), but Lambdoceras had a narrow snout and probably browsed from small trees and shrubs.

The distinctive horns seem to have been well-suited for both visual display and intraspecific combat. With the wide variety of headgear available, protoceratids could identify their species easily and select mates with the best horns. Earlier horned species such as Protoceras probably displayed their horns sideways, while the slingshots of the synthetoceratines could only have been used in frontal display. Other characteristics show that the males could have bitten, butted, and neck-wrestled their way to dominance. While the horns were not suited for ramming at speed, they could have interlocked so as to minimize the chances of injury. As mentioned previously, even the most primitive species were already specializing for intraspecific combat (Norris, 2000).

Oh, and a final note to paleo-artists and paleontographers: how about painting less theropods and more protoceratids? There's precious little that shows up in a Google image search, you know. They do crop up from time to time, though. For starters, there's a Knight pic of Dinictis chasing Protoceras, and Zallinger's Age of Mammals mural has the "Big Three" protoceratids - Protoceras, Syndyoceras, and Synthetoceras.


References

Barnett, L. and the editors of Life. The World We Live In. 1955

Norris, C. A., 2000: The cranium of Leptotragulus, a hornless protoceratid (Artiodactyla: Protoceratidae) from the Middle Eocene of North America.
Journal of Vertebrate Paleontology: Vol. 20, #2, pp. 341-348

Prothero, Donald R. in Janis, Christine M.; Scott, Kathleen M.; and Jacobs, Louis L. Evolution of Tertiary Mammals of North America, Vol. 1. Cambridge University Press, 1998

Solounias, N., and Moelleken, S.M.C. Dietary Adaptation of Some Extinct Ruminants Determined by Premaxillary Shape. Journal of Mammalogy, Vol. 74, No. 4 (Nov., 1993), pp. 1059-1071

There's going to be a sneak preview...

... and the sneaks ain't gonna like it. (kudos to you if you get the reference).

The next paleo-post will discuss an extinct family diagnosed by the following characters: a strong upper molar lingual cingula, a short coronoid process on the mandible, a concave proximal side of the sustentacular facet of the astragalus, and an absent third metacarpal.

Oh, and they've got some interesting headgear (whoops, I've said too much already).

Folded mountain

A remarkably folded mountain - note how the strata start off nice and tidy to the left, and then get all scrunched up in the middle. I can't think of a better way to illustrate the power of tectonic folding.

The fine art of Mesozoic Mortal Combat

I recently had the pleasure of digging up a set of old dinosaur posters that I thought I had lost long ago. I can't recall exactly where they came from, but I assume they were bundled with some red-blooded boy's magazine. The posters, at any rate, certainly are red-blooded, and fit into the venerable tradition of the Dinosaur Fighting Pair - two dinosaur species locked in bloody combat to the death.
I shall share some of the best with you, since every paleontologist harbors a secret desire to see dinosaurs ripping each other to bits. The violence here isn't as bad as in some other media, but it's still stirring stuff.


The series' Allosaurus chasing a Brachiosaurus, though, always scared me. I mean, look at that mug! That has got to be the most ghoulish, monstrous Allosaurus ever depicted in art. Well, to be honest, I think the artist was trying some sort of dramatic foreshortening, but it didn't really work out.


The other Allosaurus poster, though, is much better. There's Allosaurus rearing up in pain as Stegosaurus drives its thagomizer down the predator's throat - ow. There's even the obligatory volcano spewing its ash in the background. Which reminds me - erupting volcanoes are nearly mandatory in vintage paleo-art. Even Rudolf Zallinger, in his Age of Reptiles, obliged.


What is wrong with this picture on the left? If you said to yourself "Deinonychus is from the Aptian-Albian and Triceratops is from the Maastrichtian", then you can move directly to GO, collect $200, and start a career in paleontology. Nevertheless, the obvious impossibilty of the picture doesn't stop Triceratops from defending itself ably. Besides, anachronisms are nothing new in popular dinosaur imagery. At least the anachronism here isn't as bad as in Disney's Rite of Spring, where Tyrannosaurus fights Stegosaurus (!), as Apatosaurus (!!) and Dimetrodon (!!!1!) look on.


However, this poster is without a doubt my favorite. The armored dinosaur is labeled as Tarchia, and the carnivore getting its head bashed in is Chilantaisaurus (yes, that's right - look in the top left corner if you don't believe me). The makers of the posters actually took the effort of discovering two relatively obscure Asian dinosaurs and putting them together! I can only hope many children were surprised by this poster, and actually got to learn something new. That said, Tarchia is from the Campanian-Maastrichtian of Mongolia and Chilantaisaurus is from the Berriasian-Albian of China, so maybe they were overplaying their hand. Besides, Tarchia looks suspiciously like Sibbick's Euoplocephalus (Chilantaisaurus was probably a spinosaurid, but I'll waive that as no-one knew it back then).

There are two other posters - Camarasaurus showing Ceratosaurus its thumbs, and two Tyrannosaurus squabbling over a carcass, but they're largely irrelevant.

Close Encounters of the Blurred Kind: the chameleon

This relatively amiable Mediterranean chameleon (Chamaeleo chamaeleon) was trying to cross the road at AUB and running into a wall. I helped him get to the trees, where I released him.

Note that Mediterranean chameleons are not as cuddly as they look. First of all, they're quite aggressive. When you run into them, they're usually black with rage. Second, they can bite. Hard. My policy with them is mainly to let them clamber all over my hand (and eventually, arm, body, and possibly face) while I move them from one location to another, in order to minimize stress and make them feel at home.

Under no circumstances should you try to keep a Mediterranean chameleon at home. We had two of them as live specimens at the biology labs, and both died after refusing to eat for weeks. If you really must have a chameleon, get yourself a captive-bred chameleon of a different species.

Swimming bone shears: the bite of the great barracuda

The great barracuda Sphyraena barracuda is an impressive marine predator found in tropical seas around the world. In appearance much like a pike, the great barracuda uses a lie-in-wait strategy, which consists of waiting for fish prey to pass by before striking suddenly and dispatching its victim. While not encumbered by the unfortunately gruesome reputation of sharks, great barracudas have been known to attack humans on occasion, sometimes severing limbs. However, the bite mechanics of the barracuda's strike have been studied only recently, in Grubich et al. (2008).


The distinctive underbite of barracudas conceals a remarkable set of teeth, probably a unique feature to them and the barracudinas (Paralepididae). The large teeth at the end of the premaxillary and dentary are there merely to stop fish from escaping a barracuda's jaws - the real cutlery is in the back of the mouth. Barracuda teeth can be sharper than shark teeth, and even a dead barracuda can cause injury if you do something stupid, like putting your finger in its mouth (trust me, I've seen it happen).


At the end of the barracuda's mouth, teeth on the dentary oppose razor-sharp teeth on the palatine. The close fit of these teeth causes them to slice past each other like scissors (note the inset pic of bone shears in the lower picture). The barracuda uses these teeth to slice fish up with remarkable efficiency, one which invariably results in fish being bitten in half*.

* "Back halves" of fish are all too common in barracuda stomachs.

Barracudas feed by ram-feeding - moving rapidly and forcing water (and prey) into their mouth. However, the authors state that the attack of a barracuda is beter described as ram-biting - the barracuda delivers a debilitating bite right after the attack, which happens at speed. Ram-biting is used by fish to kill and butcher large prey safely. Apart from barracudas, other known proponents of ram-biting include big sharks such as the white shark and fast swimmers such as tuna and wahoo. Even the extinct placoderm Dunkleosteus (!) is mentioned as a possible ram-biter, in Anderson and Westneat (2007).



These motion captures, with a juvenile great barracuda finishing off a goldfish, show just how rapid the strike of a barracuda is. The left sequence shows the initial strike; the right sequence shows post-strike biting and food processing.

To my amusement, it turns out that there are barracudas in our part of the world, only they come with a clever marketing ploy. When caught young, they're called mallifa, and when caught mature, they're called sfirneh (probably a corruption of Sphyraena). And to think I always thought they were two different fish!

All pictures from Grubich et al. (2008).


References

Grubich, Justin R.; Rice, Aaron N.; and Westneat, Mark W. Functional morphology of bite mechanics in the great barracuda (Sphyraena barracuda) Zoology, Volume 111, Issue 1, 17 January 2008, Pages 16-29

Erlikosaurus andrewsi, a pot-bellied king of the dead

I'll freely admit it. Erlikosaurus is one of my favorite dinosaurian genus names. It translates directly to "Erlik's lizard", with Erlik being the Siberian/Mongolian god of the dead. According to legend, Erlik was one of those cunning gods, who, wouldn't you know it, ends up creating humanity and so getting banished to the underworld for his trouble. I always wondered why on earth was a pot-bellied, long-necked plant-eater saddled with a name better suited for, say, a tyrannosaur, but it still is cool. The andrewsi bit, of course, honors Roy Chapman Andrews.


Erlikosaurus andrewsi (Barsbold and Perle, 1980) is a reasonably well-known therizinosaur from the Turonian-Campanian of Baysheen Tsav, Mongolia. The holotype, GI 100/111, includes both feet, a humerus, a few cervical vertebrae, and a finely-preserved skull (lacking the mandible). Erlikosaurus is generally diagnosed as being medium-sized with laterally compressed pedal unguals, and differs from Segnosaurus in being smaller, with a longer toothless section to the mandible, more teeth, and laterally compressed pedal unguals. (Glut, 1997).

Picture, from here, shows the skull of Erlikosaurus and the pelvis of Segnosaurus - the clues to building up the composite "segnosaur".

With the pelvis unknown, the assignment of Erlikosaurus to the "Segnosauridae" was tentative at best, since the unusual therizinosaur pelvis was diagnostic of the group. A later study by Barsbold and Maryanska (1990) firmly established Erlikosaurus as a segnosaurid.
The skull of Erlikosaurus is the best therizinosaur skull known (not to mention of the best therizinosaur specimens, period), and was one of the elements leading to the first conjectural reconstruction. The presence of a toothless beak in front of small pointed teeth was hitherto unknown in the theropods, and led to the positing of a wide variety of lifestyles, including anteaters and fisheaters. Nowadays, therizinosaurs are generally believed to be plant-eaters, the dinosaurian equivalents of ground sloths.

Erlikosaurus was likely the closest therizinosaur to Therizinosaurus itself, and as such was probably very similar. It is also very similar to Segnosaurus, and the pelvic girdle GI 100/84, referred to as the holotype of Enigmosaurus mongoliensis, may arguably belong to Erlikosaurus. Finally, various Mongolian therizinosaur eggs may also belong to Erlikosaurus.

References

Glut, Donald F. Dinosaurs - The Encyclopedia. 1997. McFarland & Compny, Inc., Publishers.

Norman, D. The Illustrated Encyclopedia of Dinosaurs. 1985. Salamander Books, London