And check out the seventh installment of Linneaus’ Legacy, over at The Ethical Palaeontologist.

Last week, Roxanne and I (along with a handful of other folks from the NMMNHS) popped up to Denver for the Annual Meeting of the American Association of Museums. Lots of nifty stuff to see and hear, Denver’s great selection of museums to visit, and among the thousands of attendees were plenty of old contacts to catch up with and new museum folk to meet. I sat in on several great sessions dealing with museum exhibitry, interactive tech, and engaging web visitors, and as I spent some time going through my notes I’ll keep an eye out for interesting tidbits to post here. But for now I’ll put up some quick pics from the Museum Expo—dozens of vendors of all stripes packed into the Exhibit Hall of the Colorado Convention Center.

As might be expected, my picture-taking skewed heavily toward the paleo:

A cast Velociraptor skeleton and life restoration at the Pangaea Partners booth. Very nice coloring/patterning on the feathers:

This beauty was sculpted by Dennis J. Wilson of Pangaea Designs.

A rather different flavor of feathered theropod was on display at the Phil Fraley Productions booth:

This fantastically meticulous restoration of a dodo (on the left, of course) was commissioned by the Raffles Museum of Biodiversity in Singapore. Reprints of a pair of articles detailing the work that went into this piece were available at this booth, but are also available for download from this page.

The above models of a lobefinned fish and early tetrapod caught my eye at the Whitman Zahourek Foundation booth. The Foundation promotes anatomy education, and brought to my attention the Anatomy in Clay classes/manikins, which provide plastic skeletons of dogs, horses, and humans that allow for the attachment of plasticine “soft tissue” structures, as in the muscles attached to “Caniken,” below:

For me, this looks to be an excellent way to gain a more intuitive understanding of how muscle attaches to bone in paleo-restorations—certainly much less ‘visceral’ than dissection. Not that I’ve got anything against viscera, mind you, but I’ve always preferred additive processes to reductive ones. I’ll definitely be looking further into this.

Wish I could say that I’ll be posting more regularly, but I’m afraid things are going to continue to be slow here as I focus most of my time/energy into the upcoming Triassic exhibit at the Day Job—when I last mentioned it we were shooting for a March deadline, but the final opening date has since (thankfully) been set at May 17th. Now less than two weeks off…

• New pterosaur: Raeticodactylus filisurensis
• Name means: (Wing) Finger from the village of Filisur, in Raetia (the old name for the Swiss Canton Grisons, where it was found)
• Relations: Basal pterosaur
• Location: Eastern Switzerland
• Age: Late Triassic, ~203,000,000 years ago
• Material: Nearly complete skull, partial postcrania
• Wingspan: 135cm (~4.5 feet)
• Info: The oldest known pterosaur fossils come from late in the Triassic period, when this finger-winged group of reptiles first took to the skies. Newly-described Raeticodactylus adds to the handful of currently known Triassic pterosaurs. Raeticodactylus sported a unique crest above its nose, a deeply-keeled lower jaw, and a unique combination of teeth—fangs at the front of its mouth with wrinkled enamel on the inside, and crunching teeth further back in its jaws tipped with three to five cusps. Its limbs were long and thin compared to its contemporaries, giving it about twice the wingspan of the most famous Triassic pterosaur, Eudimorphodon ranzii. And, oddly enough, the head of its femur is offset 90° from the shaft, suggesting an upright stance more similar to that of dinosaurs than other pterosaurs.
• Reference: Stecher, R. 2008. A new Triassic pterosaur from Switzerland (Central Austroalpine, Grisons), Raeticodactylus filisurensis gen. et sp. nov. Swiss Journal of Geosciences doi: 10.1007/s00015-008-1252-6.
• Web coverage:
  • Laelaps
  • When Pigs Fly Returns 1 & 2
  • David Hone’s Blog
  • microecos

First up, Will at The Dragon’s Tales has had a couple of great articles on two of the more charismatic groups from the latter days of the Paleozoic: the carnivorous, sabre-toothed gorgonopsians and the herbivorous, tusk-beaked dicynodonts. Plus, he notes that there are some fantastic restorations of Permian vertebrates showing up on Wikipedia.

Speaking of dicynodonts, The Lord Geekington, mentions the ubiquitous Permo-Triassic straddler Lystrosaurus in his review of aquatic habits in stem-group synapsids. At the other end (that is, the beginning) of the Permian, he also discusses the potentially piscivorous pelycosaur Ophiacodon.

Finally, I recently came across the Houston Museum of Natural Science’s Prehistoric CSI blog, whose archives are chock full of fossil finds from Seymour, Texas—a treasure trove of Early Permian vertebrates—with videos and photos, and field sketches by Dr. Robert Bakker.

This insight into the chondrichthyan condition brought to you by The Western Nostril.

Tip of the toupee to the good bloggers at Drawn!

According to Wikipedia, the WIPP site was chosen, in part, because the salt deposits have remained relatively stable since they precipitated from a receding Permian sea, over 250,000,000 years ago. Presumably, the same stability helped preserve the earliest direct evidence of biological life—nearly four times the age of the previous record holder: traces of protein from 68 million year-old T. rex fossils.

Cellulose microfibers, from the UNC News press release.

Cellulose microfibers were the most abundant biological materials found, although the article tantalizingly mentions that some evidence of ancient DNA was “observed.”

Now a quarter-billion year-old bit of biomass is pretty darn nifty, and since the research is published in April’s issue of Astrobiology it leads to some interesting ideas about the possibility of finding durable bio-molecules preserved in salt deposits on other worlds. But I think there’s far greater potential for speculation here. I mean, we’ve got Paleozoic biology in proximity to low-level radiation. Forget the atom-bomb triggered monster ants of THEM!—imagine a pickled monuran, revivified and grotesquely enlarged by the careless placement of a used radiation suit, leaping out across the desert as it attempts to satisfy 250 million years worth of salt-cured hunger…

But, it seems well past time to work on putting some content up here, so I’ll fix as I go. If there are any long-suffering readers still out there, please let me know if anything isn’t working with the new design. Ideally, we’re all seeing something that looks a little like this (well, maybe somewhat larger):

More soon!

Meet Indohyus

The image above, created by artist Carl Buell, shows a charming little animal called Indohyus, about the size of a modern raccoon, that lived some 50,000,000 years ago in what is now northern India. Indohyus is a member of the Raoellidae, an obscure, extinct family of hoofed mammals closely related to the artiodactyls (even-toed hoofed mammals, currently represented by pigs, hippos, camels, deer, etc.) Raoellids are only known from Eocene-aged (56–34 million year-old) fossils from southern and southeastern Asia.

Like any good group of obscure, extinct mammals, the raoellids were primarily known from fossil teeth. Until this week, that is, when a team of scientists led by Hans Thewissen described new cranial and postcranial fossils of Indohyus in the journal Nature. These new fossils are helping to provide a more complete picture of raoellid appearance, life habits, and possible relationships.

She is heavy, she’s my sister

As the restoration above shows, Indohyus was a long-legged animal, with the characteristic “double-pulley” ankle that gives artiodactyls a little extra swing to their step. Yet despite it’s relatively graceful profile, the walls of the bones of Indohyus are much thicker than in most other mammals. This is an adaptation commonly seen in aquatic animals, where thick bones act as ballast—helping them move underwater without automatically floating to the surface. Thewissen et al. suggest that the heavy skeleton of Indohyus allowed it to walk along the bottom of rivers and lakes, possibly as protection from predators or to help it search for food. Analysis of isotopes within the fossils add some additional weight (no pun intended) to this aquatic hypothesis.

The semi-aquatic lifestyle of raoellids seems to have been the start of something very big. Key features in the skull of Indohyus led Thewissen and his team to the conclusion that raoellids were the closest known relatives (or sister group) to whales.

Indohyus by Carl Buell

The Telltale Involucrum

Indohyus shares several dental features with early whales, including a front-to-back arrangement of the incisors, high crowns on its back molars, and similar wear facets. But the clincher is a little thickened lip of bone on the inside of the middle ear cavity, known as the involucrum, which likely assists in hearing underwater. Until this week, only whales were known to possess this feature. But one of the new Indohyus skulls shows that this little raoellid had a lovely little involucrum as well (see it here, and be amazed).

Shaking the Tree?

We know from the fossil record that, back when whales had ankles, they had double-pulley ankles. But exactly where whales fit into the artiodactyl family tree has been a matter of some debate. Molecular studies showed a close relationship to hippos, but there is a 35 million year gap between the oldest fossil whales (50 million years old) and the presumed origin of the Hippopotamidae (15 million years ago). Some researchers have held up the pudgy, long-faced anthracotheres as relatives of both hippos and whales, but the middle ear of Indohyus is very strong evidence that the little, long-legged raoellids were the whales’ closest kin.

That still leaves the question of how raoellids are related to other artiodactyls. Thewissen et al. propose a phylogeny showing that, as raoellids are the sister group to whales, then whales + raoellids form the sister group to all other artiodactyls. This keeps a close relationship between the whales, raoellids, and artiodactyls (as shown by their similar ankles), but removes whales from a close relationship to any particular artiodactyl lineage, such as hippos or anthracotheres.

Still, the classification of cetaceans has changed quite a bit in the past 15 years or so, and it will be interesting to see what future studies and discoveries have to say on the topic.

Reference:

Thewissen, J. G. M., Cooper, L. N., Clementz, M. T., Bajpai, S., and Tiwari, B. N. 2007. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature vol. 450, 20/27 December 2007, pp. 190–195.

Elsewhere online:

• The Loom: Whales: From so Humble a Beginning…
• Laelaps: Shaking the Cetacean evolutionary bush: Indohyus and the origin of whales
• Greg Laden’s Blog: A Whale of a Missing Link : Indohyus
• Pharyngula: Indohyus
• Pondering Pikaia: Transitional whale ancestor unveiled
• National Geographic News: Whales evolved from tiny deer-like mammals

And a big thanks to Carl Buell for graciously granting permission to reproduce his excellent art in this post!

This Saturday, she’ll make serious headway towards that goal by drawing 24 mammals in 24 hours as a fundraiser for Defenders of Wildlife. Donate at least $25, pick a mammal, and Jennifer will add it to her schedule on December 22. And she’ll send you the drawing! Support art, wildlife, and mammalian diversity all in one fell swoop. Not too shabby.