Field of Science

Revisiting the Cranial Anatomy of the Thalattosaur Anshunsaurus huangnihensis

Cheng, L., Chen, X., Zhang, B., and Y. Cai. 2011. New Study of Anshunsaurus huangnihensis Cheng, 2007 (Reptilia: Thalattosauria): Revealing its Transitional Position in Askeptosauridae. Acta Geologica Sinica (English Edition) 85: 1231–1237. doi: 10.1111/j.1755-6724.2011.00584.x

Abstract - The skull of Anshunsaurus huangnihensis Cheng, 2007, especially the skull roof, is described in detail in this paper. Compared to other genera and species of Askeptosauroidea, Anshunsaurus huangnihensis has some important transitional characters from Askeptosaurus italicus to Anshunsaurus huangguoshuensis: the rostral length related to the skull length between Askeptosaurus italicus and Anshunsaurus huangguoshuensis; the postfrontal existing but distinctly reduced; the posterolateral process relatedly short and overlapping the parietal. The phylogenetic analysis weakly supports the evolutional progress from Anshunsaurus huangnihensis to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the node among the Askeptosauridae ingroup. The evolutional direction of Askeptosauridae should be from Askeptosaurus italicus to Anshunsaurus huangguoshuensis. The skeletal ratios indicated that the evolutional progress is Askeptosaurus italicus -- Anshunsaurus huangnihensis -- Anshunsaurus huangguoshuensis. In biogeography provinces, the Askeptosauroidea taxa from south China have a close relationship with those from western Tethys; however, Xinpusaurus from the Late Triassic is more related to those from the eastern Pacific.

New Open Access Paper Publishing Field Notes from the 1932 Excavations at Trossingen, Germany

Schoch, R. R. 2011. Tracing Seemann’s dinosaur excavation in the Upper Triassic of Trossingen: his field notes and the present status of the material. Palaeodiversity 4: 245–282.

Abstract - The field notes of Reinhold Seemann, who conducted the 1932 dinosaur excavation at Trossingen, are published for the first time. An English translation of the whole text is also provided. Quarry maps and stratigraphic sections were redrawn and compared with new data gathered in ongoing excavations. Of the 65 finds listed by Seemann, only 21 have survived the Second World War (Plateosaurus: 18, Proganochelys: 3). This includes most of the well-preserved skeletons, which had been moved to safe places during the war. An overview of these finds and their present state is given for the first time. This reveals major differences in preservation of bones, and it adds to the knowledge of bone completeness classes at Trossingen. The missing finds were probably destroyed by fire in 1944, and there are no remains from these specimens left. In combination with the field notes and sketches, the new data on Seemann’s material may serve as a platform for future studies of and excavations at the Trossingen lagerstaette.

There Goes "Dicynodon" Biostratigraphy!

In the latest Journal of Vertebrate Paleontology Memoir Christian Kammerer, Kenneth Angielczyk, and Jörg Fröbisch (an allstar team of synapsid workers) readily handle the taxonomic mess more commonly known as Dicynodon. They find that the taxon is polyphyletic, is restricted to two species, and reassign all of the other material to a variety of old and new genera. Moreover, I think that their abstract sets a record for the number of included taxonomic names. 

Hey guys, want to tackle "Rutiodon" next?

Kammerer, C. F., Angielczyk, K. D., and J. Fröbisch. 2011. A comprehensive taxonomic revision of Dicynodon (Therapsida, Anomodontia) and its implications for dicynodont phylogeny, biogeography, and biostratigraphy. Journal of Vertebrate Paleontology 31, Supplement 1: 1-158 DOI:10.1080/02724634.2011.627074

Abstract - The dicynodont wastebasket genus Dicynodon is revised following a comprehensive review of nominal species. Most nominal species of Dicynodon pertain to other well-known dicynodont genera, especially Oudenodon and Diictodon. Of the Karoo Permian species that are referable to "Dicynodon" sensu lato, we recognize four common, valid morphospecies: Dicynodon lacerticeps, D. leoniceps, D. woodwardi, and Dinanomodon gilli, comb. nov. Eleven additional species of "Dicynodon" are recognized worldwide: D. alticeps, D. amalitzkii, D. bathyrhynchus, D. benjamini, D. bogdaensis, D. huenei, D. limbus, D. sinkianensis, D. traquairi, D. trautscholdi, and D. vanhoepeni. Morphometric analysis of D. lacerticeps and D. leoniceps specimens recovers statistically significant separation between these species in snout profile and squamosal shape, supporting their distinction. A new phylogenetic analysis of Anomodontia reveals that "Dicynodon" is polyphyletic, necessitating taxonomic revision at the generic level. D. benjamini and D. limbus are basal cryptodonts, whereas the other valid "Dicynodon" species are basal dicynodontoids. The genus Dicynodon is restricted to D. lacerticeps and D. huenei. We reinstate use of Daptocephalus, Sintocephalus, Turfanodon, Daqingshanodon, Jimusaria, and Gordonia for other species. We synonymize Vivaxosaurus permirus and Dicynodon trautscholdi (as V. trautscholdi, comb. nov.) We establish new generic names for several species formerly included in Dicynodon: Peramodon amalitzkii, comb. nov., Keyseria benjamini, comb. nov., Euptychognathus bathyrhynchus, comb. nov., Syops vanhoepeni, comb. nov., and Basilodon woodwardi, comb. nov. Of the main Karoo Permian taxa, Dicynodon, Basilodon, and Dinanomodon range throughout the Cistecephalus and Dicynodon assemblage zones, but Daptocephalus is restricted to the Dicynodon Assemblage Zone.

Hitchcock's Birds

Brian Switek has a wonderful post on the dinosaur trackways of New England over at the Dinosaur Tracking Blog.  I grew up in Connecticut and as a boy enjoyed going to Dinosaur State Park to see the trackways.  My first foray into the Triassic.

David Peter's Take on Revueltosaurus

David Peters has a new post up on his blog that has been getting some attention including on Facebook.  I'll address it shortly but first I'd like to apologize for the long delay in getting the full description of this taxon out in publication, especially since everyone has now seen Jeff Martz's amazing reconstruction. Originally I suggested he submit it for the Lanzandorf prize because I thought the paper would actually be submitted by that point. The main text has been near completion for some time now and very recently revised.  The hang-up is in completing the figures and because I keep taking on other tasks and responsibilities keeping me from focusing on the project. 

David Peters post with the suggestion that Revueltosaurus may be a paracrocodylomorph is actually fairly insightful given that he has not seen the material first hand and is relying solely on preliminary descriptions and Jeff's reconstruction.  Revueltosaurus is an amazing critter because it possesses character states found in a variety of suchian taxa, including paracrocodylomorphs; however, it has many characters only shared with aetosaurs which results in the position found by Nesbitt (2011). Sterling's coding was based on a thorough examination of all presently known material and although I don't agree with 100% of his codings I don't think the phylogenetic position of Revueltosaurus will change with the publication of the full description and revised phylogenetic analysis.

I'd ask everyone to please be a bit more patient and we'll get the paper out. I realize that it is an important taxon and as a result a lot of people want/need to see the material.

Aetosaurs Made Brachychirotherium Footprints

Lucas, S. G., and A. B. Heckert. 2011. Late Triassic aetosaurs as the trackmaker of the tetrapod footprint ichnotaxon Brachychirotherium. Ichnos 8: 197-208 DOI:10.1080/10420940.2011.632456

Abstract - Brachychirotherium is the common ichnogenus of Late Triassic chirothere footprints well known from western Europe, North America, Argentina and South Africa. Although it has long been agreed by most workers that the trackmaker of Brachychirotherium was a derived crurotarsan archosaur, the trackmaker has been identified as either a rauisuchian or an aetosaur, and some workers attribute it to a primitive crocodylomorph (sphenosuchian). New knowledge of the osteology of the manus and pes of a large aetosaur, Typothorax coccinarum, indicates a close correspondence between the manus and pes structure of aetosaurs and the morphology of Brachychirotherium. Furthermore, functional analysis of complete skeletons indicates aetosaurs plausibly placed their feet in the narrow gauge, nearly the overstepped walk characteristic of Brachychirotherium. Brachychirotherium and aetosaurs have matched distributions, that is, they were Pangea-wide during the Late Triassic. The manus and pes morphology of rauisuchians and early crocodylomorphs (sphenosuchians) deviate from Brachychirotherium footprint morphology in key features, thus excluding their identification as trackmakers. Aetosaurs made Brachychirotherium footprints.

Archaeologists vs. Paleontologists

The following blurb is from
The rivalry between archaeologists and paleontologists has been around ever since Hanna Barbara leaked top secret documentary footage showing that humans, dinosaurs, and Pleistocene mega fauna coexisted. This has led to a sibling rivalry, in which neither party can safely work beside the other, for fear of Indian burns, and getting told on to mom and dad. This forces each party to work in complete isolation from each other.
Archaeologists, for their part, hate paleontologists, because nobody in the general public knows what archaeology is, and the general public mistakenly assumes that they are looking for fossils of extinct animals. Paleontologists hate archaeologists for similar reasons, because the general public always asks them if they are archaeologists, and assumes they are looking for buried treasures, such as artifacts, coins, and arrowheads, and constantly asks archaeologists if they are paleontologists.
Public, Please get it right; Archaeologists look for people. Paleontologists look for animals.
I think almost all of us in the paleo profession have encountered this at one time or another explaining what we do to old friends, family, and the public. I've found when I try to correct them I'm just met with blank stares, especially if I try to go beyond the term "dinosaur" at all, so I usually don't bother anymore. It always amazes me that the public is certainly familiar with both terms but consistently gets them backwards when it come to the objects of interest. I've also heard what the first sentence of the article is hinting at, that most people's (Americans at least) only interaction with paleontology is through the Flintstones TV show.  Moreover I also have a hunch that this confusion may be why there are so few paleontologists employed by the U.S. government compared to thousands of archaeologists. A colleague blames the Cope vs. Marsh bone wars for souring the government on paleontology, but I think they might just be confused about the terms and historically thought they actually had it all covered. After all isn't that what archaeologists study?

Kyrgyzsaurus, a new Drepanosaur from the Triassic Madygen Formation of Kyrgyzstan

Alifanov, V. R., and E. N. Kurochkin. 2011. Kyrgyzsaurus bukhanchenkoi gen. et sp. nov., a new reptile from the Triassic of southwestern Kyrgyzstan. Paleontological Journal 45(6): 639-647 DOI: 10.1134/S0031030111060025

Abstract - A new reptile, Kyrgyzsaurus bukhanchenkoi gen. et sp. nov., from the Triassic (Madygen Formation) of southwestern Kyrgyzstan is described based on the anterior part of the skeleton (skull, cervical and anterior dorsal vertebrae, ribs, pectoral girdle) and skin imprints. This is the most archaic representative of the family Drepanosauridae (Archosauromorpha, Diapsida). The most prominent features of the new form are the shortened lower jaw, numerous teeth, granular body osteoderms, large supraorbital shelflike skin folds, and thick and extensive throat sac.

New Paper on Permo-triassic Therapsids from Eastern Europe

M. F. Ivakhnenko, M. F. 2011. Permian and Triassic Therocephals (Eutherapsida) of Eastern Europe. Paleontological Journal 45: 981-1144 DOI: 10.1134/S0031030111090012

Abstract - Cranial morphology of Permian and Triassic Therocephalia of Eastern Europe is revised. The Therocephalia are regarded as an order of the subclass Eutherapsida of the class Theromorpha. Phylogenetic relationships are reconsidered and a tentative taxonomic scheme of the order is proposed. Biomorph evolution of East European Therocephalia from the Middle Permian to the Middle Triassic are discussed.

Aesop's Fable - The Triassic version - the Dinosaur and the Crocodile

You can read it here:

Triassic palaeontology in the Economist.