Monday, December 31, 2012

2012 in Review: Advances in Marine Mammal Paleontology

Even though it's already twelve or so hours into 2013 here, since most of my readers are still in 2012 at the moment I thought I'd take some time to do a brief review of new research on fossil marine mammals published during the last year. It's been a good year for the pygmy right whale, and sirenians. Not much has been done with fossil pinnipeds, unfortunately (but stay tuned... especially around mid-January...).



I'm doing this in alphabetical order of the author's last name - so I promise that a taphonomic article coming first does not reflect my own bias. Early in the year Zain Bela├║stegui and colleagues published on a Miocene mysticete skeleton in PPP which was not only articulated, but also had a number of flask-shaped Gastrochoenolites borings in it. Such borings are common in marine mammal bones, particularly those from lag deposits like the Red Crag in eastern England, as well as the Santa Margarita Sandstone in California. But bored remains from those units are all allochthonous, and the fact that the skeleton was still articulated meant that it was autochthonous, which is a pretty surprising find in my opinion. They also did a great job at summarizing previously published biogenic bone modifications (admittedly a better job than I did in my bite marks paper).

I've already covered Michelangelo Bisconti's publication in Zoological Journal of the Linnean Society on the new neobalaenid (or neobalaenine...?) genus Miocaperea from Peru, which you can check out here. Miocaperea is not the first pygmy right whale to be reported from the fossil record (see below), but it is the first non-fragmentary specimen - and at 7-8 million years old, it indicates that the modern Caperea morphology has been around for a long time.


Although technically not published yet, a recent paper in PPP (online early) by Mark Clementz, my adviser Ewan Fordyce, UW student Stephanie Peek, and UM professor David Fox (who during the 2009 MSU geology field camp final mapping project, I ran into out at Frying Pan Gulch - the U. Minnesota field camp was out there at the same time; Dave is a co-supervisor for my good friend and taphonomy cohort Laura Vietti's Ph.D.) focuses on oxygen and carbon isotopes of Oligocene cetaceans from New Zealand and South Carolina. They studied odontocetes, toothed mysticetes, toothless mysticetes, and the enigmatic kekenodontids (the surprisingly dorudontine-like Kekenodon sp. in above photo). Among their findings - kekenodontid isotopes changed from anterior teeth to posterior, probably reflecting ontogenetic changes from nursing to adult feeding. Low O and C isotope levels for toothless mysticetes were similar to modern mysticetes, suggesting that they already were migrating along a latitudinal gradient, and that toothed mysticetes and odontocetes were "resident" rather than transient populations.



Another paper that just recently came out by my colleague Julia Fahlke in Palaeo-Electronica uses 3D digital models to reconstruct feeding by Basilosaurus on Dorudon, based on several skulls of juvenile Dorudon with large bite marks. The mouth of Basilosaurus was opened and the skulls of poor baby Dorudon rotated until possible fits were found. A pretty neat paper with some great graphics.



Another paper on fossil neobalaenids - which I've also already talked about. This is the first reported find of a neobalaenid (pygmy right whale) in the fossil record, published by Erich Fitzgerald in JVP.


Yet another paper about Caperea... which I just posted about last week, and you can check it out here. This paper came out last week in Proceedings of the Royal Society B, published by R.E. Fordyce and Felix Marx, and includes a new phylogenetic analysis and presents the hypothesis that the modern pygmy right whale is the sole surviving member of the (formerly extinct) family Cetotheriidae.


Jonathan Geisler and colleagues published in JVP over the summer a new genus of iniid river dolphin, Meherrinia, from the Meherrin River, North Carolina, represented by numerous (about a dozen) partial skulls. At SVP in Raleigh this year, Jonathan, Brian Beatty, and Carl Mehling visited a local collector who had several more specimens he donated - in addition to some other great stuff. Meherrinia is the first diagnostic iniid fossil reported from marine rocks.



Ukrainian colleague Pavel Gol'Din and coauthor K.A. Vishnyakova published an article in APP (still in the forthcoming articles section) on a high latitude record of the southern hemisphere beaked whale Africanacetus, previously reported by Bianucci et al. (2007) from the South African continental shelf. The fossil is the highest-latitude record of a beaked whale in the fossil record, and is 6000 km from the type locality, suggesting it had a circum-antarctic distribution. Unfortunately, the age of these specimens - like the South African material - is totally unknown, but assumed to be Neogene in age.



A Pleistocene record of a bottlenose dolphin (Tursiops sp.) was reported on by Toshiyuki Kimura and colleages in the Bulletin of the Gunma Museum. Pleistocene records of marine mammals are fairly rare, and such as in this case, are mostly composed of extant genera and species.

The only paper this year (to my knowledge) on fossil pinnipeds was published by Irina Koretsky and colleagues in the journal Deinsea. In it they describe a new species of the early phocid Leptophoca from both sides of the atlantic - Leptophoca amphiatlantica, based on isolated femora. The new species is found in the Calvert Formation and Saint Mary's Formation of Maryland and Virginia, and the Miocene Upper North Sea Group in the Netherlands (from the "Hoojdonk sandpit", a whimsical name to non-dutch speakers like myself). However, it's unclear exactly how much taxonomic utility is preserved in isolated postcrania.





Korean paleontologists Y.M. Lee, D.K. Choi, and former Otago student Hiroto Ichishima published on a middle Miocene platanistid from south Korea in JVP. This new specimen is just a fragmentary (but well preserved) rostrum - at first glance, some folks would be hard pressed to tell whether this was a dolphin or an ichthyosaur. They identified this specimen as a pomatodelphine (including the Floridan fossil dolphin Pomatodelphis) rather than an allodelphinid dolphin based on tooth morphology. This is interesting, as allodelphinids are already known from the early and middle Miocene of California - but pomatodelphines are not yet known from the Pacific, giving this interesting biogeographic implications.



Japanese colleague Mizuki Murakami recently published parts of his dissertation undertaken at Waseda University regarding fossil porpoises (Phocoenidae) from Japan. He described three new genera between two articles published in the same issue of JVP: Archaeophocoena, Miophocoena, and Pterophocoena. In one of these articles, he reconstructs the facial evolution of phocoenids and other delphinoids in painstaking detail, and in the other, conducts a detailed phylogenetic analysis of delphinoids, with interesting phylogenetic results. It's also the first analysis to include fossil monodontids Denebola and Bohaskaia, as well as the bizarre creature Odobenocetops (which plots out as sister to the monodontids).



A paper in the works for a long time came to fruition this year: Yoshihiko Okazaki (Kitakyushu Museum) described a new eomysticetid from Japan which he named Yamatocetus canaliculatus. It is similar in many regards to Eomysticetus - and is more complete, and has a partial postcranial skeleton. I really ought to talk about this one in more detail later. Aside from all the usual weirdness of an eomysticetid, this taxon also appears to retain individual alveoli, which Okazaki interpreted as housing reduced teeth during life.


Silvia Sorbi and colleagues published on new remains of Metaxytherium subapennum, the geochronologically youngest sirenian in the Mediterranean and youngest species of Metaxytherium. Metaxytherium is principally a middle-late Miocene dugongid - but one relict species persisted in the Mediterranean, even after dwarfism triggered by the Messinian Salinity Crisis (for the uninitiated, the Mediterranean nearly dried up at the Mio-Pliocene boundary), and reflooding of the Mediterranean. Responding to reestablishment of the Mediterranean Sea, Metaxytherium subapennum increased in body size from its ancestors. Unlike hydrodamaline dugongids in the North Pacific, Metaxytherium subapennum was unable to adapt to colder climates and went extinct during the middle Pliocene.



Two recent papers by Tarasenko and Lopatin published in the Palaeontological Journal focus on new records of cetotheriid baleen whales from the Northern Caucasus. Two new genera were reported: Kurdalogonus from Adygea, and Vampalus from Chechnya. For the lazy, these regions of the Russian Federation lie between eastern Ukraine/Black Sea and western Kazakhstan/Caspian Sea. Kurdalogonus in some ways is very similar to Cetotherium rathkei, another cetotheriid from the former Paratethys (Ukraine to be exact). Vampalus, on the other hand, is a bit more of a freak, and was identified as a herpetocetine - although no phylogenetic analysis was conducted (although the earbones, I think, are a bit of a selling point for me). It definitely has some weird stuff going on with the braincase, and in some ways looks like a cross between a herpetocetine and an aetiocetid.


Still with me? Almost done. Early on this year, my good friend Jorge Velez-Juarbe and Nick Pyenson published in JVP a new genus of fossil monodontid, which they named after USNM collections manager Dave Bohaska. I had the pleasure of meeting Dave in October - he's very entertaining and quite a character, and goes above and beyond the call of duty to make sure you have a productive/successful USNM visit, tracking down all sorts of obscure fossils, opening storage jackets, etc. The fossil was collected in the 1960's from the Yorktown Formation at Rice's Pit in Virginia, where the type specimen of Balaena ricei was also collected. Since it was not from the Yorktown at Lee Creek, this specimen was not described by Whitmore and Kaltenbach (2008) in the Lee Creek IV volume, where they described all sorts of monodontid earbones and partial skulls/mandibles as Delphinapterus (modern beluga). Now it appears that two monodontids were present (or, alternatively, everything may be referable to Bohaskaia).



Another paper by Jorge and colleagues early in the year, published in PLOS One. This paper discusses feeding ecology in three sympatric sirenian assemblages from the late Oligocene of Florida, early Miocene of India, and early Pliocene of Mexico. Each of these assemblages included three dugongid sea cows, and although body size and certain feeding adaptations did overlap in each assemblage, at least one consistent difference was present in each. Modern sirenians do not geographically overlap, and these assemblages appear to have evolved iteratively during the Cenozoic - in other words, different niches were haphazardly 'filled' by different species of dugongids through time (rather than the small bodied taxa being closely related and vice versa).



And another sirenian study to finish off 2012. German researcher Manja Voss recently published in Palaeontologische Zeitschrift on a new skeleton of Halitherium schinzii from the early Oligocene of western Germany. This specimen suggests that some taxonomic revision for the species is required. Interestingly, some figures in this paper look like there are Osedax pockmarks on the bones of this animal.

Have a productive 2013 - I didn't get anything published in 2012, although as alluded to above, keep your eyes peeled mid-January; I've got three other papers in review at the moment, and a couple more nearing submission, so 2013 is going to be a good year for me, I can tell already. 

Some of these studies I really ought to talk about in further detail, but I'm sick of typing (and if you're a healthy human being, you're probably sick of reading this). In any event, it's New Year's Eve, stop reading the internet and go to a party already!

Friday, December 28, 2012

US research trip part 9: Charleston, South Carolina, and the Charleston Museum

Given my research focus on eomysticetid baleen whales, it was necessary for me at some point during my Ph.D. to travel to Charleston, South Carolina, to visit Al Sanders and photograph the holotype of Eomysticetus whitmorei. This was the number one objective for my entire month-long excursion. I absolutely loved Charleston, and would love to have an excuse to return.


We moved to New Zealand in March, after a short California winter and after about a month of "nice" weather in Dunedin, were plunged back into four months of winter - we basically had an entire year of winter. Oddly enough, even though it was late October, my visit to Charleston was the first time I felt warm outside since my move to New Zealand. It was also the first time in a long while I could comfortably wear a T-shirt at night in a long while. I really enjoyed Charleston - it's a beautiful city, with so many historical buildings you nearly trip over them.


St. Michael's Episcopal Church, the oldest church in Charleston, built in the 1750's. The plaque on the side of the church claimed several signers of the Declaration of Independence as members (several of whom were interred in the adjoining cemetery).


Fort Sumter, as viewed from waterfront park on the east side of Charleston. It's the tiny one on the right, next to the radio antenna. For the uninitiated, the American Civil War began right here in Charleston with the bombardment of the Union-held Fort Sumter (technically, the civil war opened with Citadel cadets firing upon the Union ship Star of the West). It was pretty neat seeing current students jogging around town in "Citadel" sweats (Citadel is a military academy). Just north of St. Michael's church in Charleston, you can find a plaque indicating that the previous building on the site was used for the South Carolina Assembly, where the political leaders of the state voted to become the first state to secede from the Union, shortly following the election of Lincoln.


Speaking of the civil war and all things aquatic, here's the world's first submarine to successfully sink an enemy ship, the H.L. Hunley - it's about 2 meters in diameter and about 5 meters long or so... I would not have wanted to be a crewmember (least of which because the Hunley sank several times, including after it sank the Housatonic). The first operational submarine - the Turtle - was also an American vessel, dating from the American Revolution, where it unsuccessfully attempted to sink a British ship in Boston Harbor. The Charleston Museum is the oldest museum in the United States, and was established in 1773 - to put it another way, it's doors had nearly been open for an entire century before the Civil War began.


Ah, finally onto fossils and "older" endeavors. Although the Charleston Museum primarily bills itself as a history museum, with a focus on Civil War history - it has extensive collections of Oligocene and Pleistocene mammals and marine vertebrates, mostly due to the efforts of recently retired natural history curator Al Sanders, who I had the pleasure of meeting during this trip (Al had also attended the 2006 SVP meeting, but as a shy undergrad I didn't introduce myself). Here, Ewan Fordyce is photographing parts of the holotype skull of Eomysticetus.


Because the SVP meeting was held in Raleigh, North Carolina, two other paleocetologists decided it would be an opportune time to make the trip south to Charleston. My friend Eric Ekdale (postdoc at San Diego State/San Diego NHM; with camera) flew down, and I had the privilege of driving down Ewan and former Otago Ph.D. student Tatsuro Ando, now at the Ashoro Museum of Paleontology (in background). A week earlier I politely asked Ewan if he knew how to drive on the right hand side of the road; when he explained that he learned to do so during his postdoc in Washington D.C. (before I was born), I made a mental note that I'd be the one driving from Raleigh to Charleston.


Ewan and Eric maneuver the skull parts of Eomysticetus.


Retired curator Al Sanders and current collections manager Jennifer chat in collections 
during our visit.


Eric examining the holotype petrosal of Eomysticetus; other earbones including the Micromysticetus type petrosal sit on the table.


A quick pause during furious note taking at the Charleston Museum; the holotype of Micromysticetus rothauseni sits next to my notebook.


The holotype of the diminutive mysticete Micromysticetus rothauseni, with both petrosals in articulation. It's a beautiful, if incomplete skull.


One of the infamous Oligocene seal femora from the Chandler Bridge/Ashley Formations, which I've discussed previously. It was nice to see the actual specimen.


The Charleston Museum does have a handful of paleontology related exhibits, although you still wouldn't have any idea from the exhibits that there were any fossils in collections. Here's a spectacular squalodontid, similar in size to our NZ squalodontid. This is a pretty scary looking beast.


A mount of an undescribed pelagornithid from the Chandler Bridge Formation; this one is also on display at the USNM. If I'd had time, I would have loved to have photographed the original specimen.


A mounted cast of the skeleton of Gavialosuchus, also a pretty fearsome looking creature. I think eomysticetids were the only things preserved in the Chandler Bridge that didn't have big sharp point teeth (or pseudo teeth for that matter). Actually, that may not be entirely true (stay tuned for a future post on the eomysticetid Yamatocetus canaliculatus for more on that...).

Saturday, December 22, 2012

Evolution of the pygmy right whale Caperea and the resurrection of the Cetotheriidae from extinction


I have a special place in my heart for small baleen whales. Large baleen whales have skulls (modern and fossil) that are just a pain in the ass to examine, move, photograph, measure, or excavate. When I first got started with marine mammal paleontology as an undergraduate, baleen whale earbones were great to work with as they still provide reasonable phylogenetic information, but are easy to identify in the field, easier to collect than complete skulls, and when a significant collection of them is established, inferring the diversity of a baleen whale assemblage is elementary. The discovery of a well preserved skull of Herpetocetus bramblei in the Purisima Formation in June 2007 (and to a lesser extent, a mandible of the same species from the preceding summer) catapulted me into the study of fossil cetotheriid mysticetes. Cetotheres were formerly considered a wastebasket group, a neglected heap of misfit toothless mysticetes that didn’t belong in modern families. These were found to belong to two phylogenetic groups: one monophyletic clade termed the Cetotheriidae sensu stricto (Cetotherium, Piscobalaena, Herpetocetus), and another group forming a paraphyletic group of early balaenopteroids, sometimes jokingly referred to as “Kelloggitheres” (Parietobalaena, Diorocetus, Pelocetus). Given my interest in true cetotheres, I was pleased to see the publication of a new article in Proceedings of the Royal Society by my adviser Ewan Fordyce and fellow labmate Felix Marx on a phylogenetic reinterpretation of the modern pygmy right whale, Caperea marginata, as an extant cetothere.



The skeleton of the pygmy right whale, Caperea marginata. From Bisconti (2012).


The modern pygmy right whale inhabits the southern ocean, and is rarely observed alive; as of 2008, only 25 sightings of Caperea have been made at sea. We know more about Caperea from dead individuals than live ones – much like working with fossils. Caperea is approximately 5-6 meters in length as an adult, dark gray, and bears a bowed rostrum with long baleen, like balaenid right whales (true right whales). Caperea feeds on copepods and euphausiids, probably employing a similar skim feeding behavior as in right whales. Unlike balaenids, the pygmy right has a falcate dorsal fin. Caperea has on rare occasions been observed in massive gregarious accumulations. The skeleton of Caperea is one of the most distinct among baleen whales: an extreme degree of cranial telescoping, a relatively short rostrum, nearly absent zygomatic processes of the squamosal, mandibles that are transversely flattened with a sinusoidal outline, bizarre earbones, posterior ribs that are expanded and flattened, and transverse processes of the lumbar vertebrae that are expanded into canoe-paddle shapes and overlap one another.


Phylogenetic results from Fordyce and Marx (2012), showing the revised phylogenetic position of Caperea marginata as a cetotheriid.




Comparison of the skulls of Caperea marginata (above) and Herpetocetus transatlanticus (below) in dorsal (left) and ventral (right) views. From Fordyce and Marx (2012).

Two previous phylogenetic hypotheses for the pygmy right whale exist. As the common name implies, morphologists have historically considered it to be related to the Balaenidae – forming a clade called the Balaenoidea. Most previous phylogenetic analyses have supported a monophyletic Balaenoidea (see summary in Churchill et al., 2012). However, molecular analyses have generally failed to yield such a relationship, and instead have found Caperea to be slightly more closely related to balaenopteroid mysticetes rather than balaenids. A recent morphological analysis by Felix Marx (2011) resulted in this intermediate position, unique among morphological analyses. In his phylogeny, Caperea showed up as a sister to the balaenopteroids, with cetotheriids, “kelloggitheres”, and balaenids further down the tree. In the new phylogeny by Fordyce and Marx (2012), Caperea was bumped down one node on the tree into the Cetotheriidae – and as a sister taxon to the Herpetocetinae in particular (Nannocetus + Herpetocetus). This resulted from the reinterpretation of several anatomical features, based on new observations of the skull morphology of Caperea. For example, cetotheriids and Caperea share a plug-like extension of the petrosal (earbone) that is exposed on the lateral surface of the skull. Like Herpetocetus, a large flange of the petrosal sticks out laterally and articulates with the squamosal bone. Certain features are obvious only in juveniles, and are obliterated during ontogeny by changes in skull shape. For example, juvenile Caperea show a rectangular extension of the maxilla that extends toward the top of the skull; this is a feature that is absent in all modern and fossil balaenids, but present in cetotheriids and balaenopteroids. Many other characters relating to the basicranium were interpreted as similar in cetotheriids, which in the analysis pulled Caperea into the Cetotheriidae.





Comparison of the earbones of Caperea marginata (left) and Herpetocetus transatlanticus (right); petrosal in articulation with squamosal above, and tympanic below. From Fordyce and Marx (2012).

So what’s so important about the reclassification of Caperea as a cetotheriid? For one, it allies a modern baleen whale with a group formerly considered to be totally extinct. The last member of the family – Herpetocetus – lasted until about 2 million years ago in the eastern North Pacific. I’m not so certain that Caperea is necessarily so closely related to the herpetocetines in particular – the fossil neobalaenid Miocaperea is contemporaneous with the oldest herpetocetine, Nannocetus eremus, and is already extremely derived; indeed, the case for it requiring a genus separate from Caperea is thin. This indicates that the hallmark pygmy right whale morphology had already evolved by the time derived herpetocetines evolved – suggesting if anything that these two groups (pygmy right whales, and herpetocetines) evolved in parallel. Neobalaenines paralleled the morphology of herpetocetines, separated from the herpetocetines in the southern hemisphere. It is unclear whether or not herpetocetines utilized a similar feeding ecology – but it is fascinating to imagine the northern hemisphere analog of Caperea going extinct at the end of the Pliocene, and the only straggler of a formerly more diverse group of dwarf baleen whales surviving in the southern ocean.

Further reading-





 References-

Churchill M, Berta A, Demere TA. 2011 The systematics of right whales (Mysticeti: Balaenidae). Mar. Mamm. Sci. 28, 497–521.

Fordyce RE, Marx FG. 2012 The pygmy right whale Caperea marginata: the last of the cetotheres. Proc R Soc B 280:20122645.

Marx FG. 2011 The more the merrier? A large cladistic analysis of mysticetes, and comments on the transition from teeth to baleen. J. Mamm. Evol. 18, 77–100.

Wednesday, December 19, 2012

US Research trip part 8: USNM osteology and mammal halls

Although a marine vertebrate specialist like myself can and will stare and drool at the mounts of fossil marine birds, reptiles, and mammals in some of the Smithsonian's halls, it is healthy to occasionally venture out and look at terrestrial mammals, other birds, and even modern fish. Well, as you'll see from the following photos, I spent most of my time taking pictures of modern marine bird and mammal skeletons anyway (oops), although I promise to my former MSU cohorts that I did spend some time looking at dinosaur skeletons (gasp!) but didn't waste any memory card space on them.


The king of the jungle, er, savannah. Beautiful mount of Panthera leo, USNM mammals hall.


The real king of the savannah, Loxodonta. It's only fair that this is the centerpiece 
of the USNM rotunda.


Back to marine mammals. Skeleton of the Fransiscana/La Plata River Dolphin, Pontoporia blainvillei. My wife just calls it (and the Californian fossil Parapontoporia) "Francis". Smithsonian Osteology hall.


A menagerie of pinnipeds: a walrus skull, a Steller's sea lion skull (Eumetopias jubatus), and my favorite pinniped, the northern fur seal, Callorhinus ursinus. I love this mounted skeleton. Smithsonian Osteology hall.


Side-by-side comparison of a sea otter (Enhydra lutra) and a river otter (Lontra canadensis). I really ought to get some work done on my Pleistocene sea otter project... Smithsonian Osteology hall.


A fantastic display showing the homology of different skull bones, showing a fish, giant salamander (or is it a goliath frog?), an alligator, a bobcat, and some kind of bird. Smithsonian Osteology hall.


A member of one of my favorite groups: an alcid, the razorbill Alca torda. The closest modern relative of the extinct Great Auk, Pinguinus impennis. Smithsonian Osteology hall.


A big beautiful swordfish, Xiphias gladius. Billfish (swordfish, marlins, and sailfish) are common fossils in some sediments.


One of the most spectacular modern mammals on display at the USNM: one of the few known skeletons of the extinct Steller's sea cow, Hydrodamalis gigas. A modern Dugong dugon on the lower right for scale.


As a surrogate New Zealander, I feel obligated to include this picture of an Apteryx skeleton.


Lastly, a barndoor skate, Raja - I love mounted chondrichthyan skeletons. I like seeing mounted or preserved specimens of Raja, because I've collected numerous calcified mandibular cartilages of a Pliocene Raja from the Purisima Formation in California (see Boessenecker, 2011).

What's up next? A summary of Ewan Fordyce and Felix Marx's new paper in Proceedings B regarding the phylogenetic placement of Caperea, the Pygmy Right Whale. After, two more posts of photos from research in Charleston, South Carolina, and then we'll be back to "normal programming".

Monday, December 17, 2012

US Research trip part 7: USNM ocean hall and hall of marine life exhibits

 I first visited the Smithsonian Natural History Museum in 2005 when I was an undergraduate, and didn't exactly have a great camera at the time. In the time being, the new Sant Ocean Hall has been installed, which includes a number of great exhibits on modern and fossil marine organisms. Here are a collection of photos I took in the Hall of Marine Life and the Sant Ocean Hall at the Smithsonian during my trip.


A beautiful mount of a sailfish (Istiophorus) in the new Sant Ocean Hall.


A sculpture of a northern right whale (Eubalaena japonica) in the Sant Ocean Hall.


A familiar face! This is a cast of the skull of the early toothed mysticete Llanocetus denticrenatus from the latest Eocene of Seymour Island, Antarctica. The skull was collected by Ewan Fordyce in Summer 1986 on an antarctic expedition. We have the original (and a cast) here in our department, currently under study by Ewan.


 The holotype mandibular fragment of Llanocetus denticrenatus, collected on an earlier expedition and named by Ed Mitchell in 1989.


A mounted cast of the skeleton of the Egyptian basilosaurid archaeocete Dorudon atrox.


A mounted skeleton of the Eocene protocetid archaeocete Maiacetus inuus from Pakistan. This is a cast of the male individual; the female - the "Good Mother Whale" - was found with the skeleton of a near term fetus inside.


A giant or Japanese spider crab, Macrocheira kaempferi, in the Sant Ocean Hall - nightmare fuel for my wife.


Dolly! Or, Dolichorhynchops as she's known to the marine reptile community. A 3-4 meter long short necked pliosaur.


Skeleton of the basilosaurid Zygorhiza from the Eocene of the southeastern US. It's about a 5 meter long animal with pretty gnarly teeth (as with all basilosaurids).


And here's the skull of Zygorhiza. It retains some primitive features, such as teeth below the orbit and heterodonty (teeth of different morphologies such as incisors, molars, etc), and several adcanced features like a posteriorly shifted bony naris and reduced hindlimbs.


The paratype skull of Diorocetus hiatus, described by Remington Kellogg in the 1960's, from the Calvert Formation of Maryland. I saw the holotype, and as mentioned in a previous post, parts of it are mostly sculpted.


Mounted skeleton of the strange Miocene pinniped Acrophoca longirostris from Peru. This long-snouted seal is well known from the Pisco Formation, and has something to do with the evolution of modern antarctic lobodontine seals.


An undescribed species of Spheniscus penguin, also from the Pisco Formation of Peru.


An early type of different flightless bird - a cast of Hesperornis, a very well known toothed swimming bird from the "middle" Cretaceous of North America, first described by O.C. Marsh from the Niobrara Formation.


Some pretty pencil urchin.


A preserved adult and juvenile coelacanth (Latimeria), a living fossil. For the uninitiated - coelacanths were known from the fossil record (Triassic, Jurassic, and Cretaceous), but thought to have gone extinct at the K/Pg boundary along with nonavian dinosaurs and other groups (e.g. ammonites, mosasaurs); a live specimen was caught off South Africa in the 1930's.