Chinleana

Tikiguania Is Not From the Triassic

2012-01-26T21:15:00.000-07:00

Hutchinson, M. H., Skinner, A., and M. S. Y. Lee. 2012. Tikiguania and the antiquity of squamate reptiles (lizards and snakes). Biology Online published before print. doi: 10.1098/rsbl.2011.1216

Abstract - Tikiguania estesi is widely accepted to be the earliest member of Squamata, the reptile group that includes lizards and snakes. It is based on a lower jaw from the Late Triassic of India, described as a primitive lizard related to agamids and chamaeleons. However, Tikiguania is almost indistinguishable from living agamids; a combined phylogenetic analysis of morphological and molecular data places it with draconines, a prominent component of the modern Asian herpetofauna. It is unlikely that living agamids have retained the Tikiguania morphotype unchanged for over 216 Myr; it is much more conceivable that Tikiguania is a Quaternary or Late Tertiary agamid that was preserved in sediments derived from the Triassic beds that have a broad superficial exposure. This removes the only fossil evidence for lizards in the Triassic. Studies that have employed Tikiguana for evolutionary, biogeographical and molecular dating inferences need to be reassessed.

New Postcranial material of Proterochampsa barrionuevoi from the Upper Triassic of Argentina

2012-01-25T21:58:00.001-07:00

Trotteyn, M. J. 2011. Material postcraneano de Proterochampsa barrionuevoi Reig, 1959 (Diapsida: Archosauriformes) del Triásico Superior del centro-oeste de Argentina. Ameghiniana 48:424-446.

Resumen - Los proterochámpsidos son miembros del clado Archosauriformes y se distinguen del resto por presentar cráneo predominantemente deprimido, transversalmente expandido en el extremo posterior, hocico angosto y alargado longitudinalmente, y narinas ubicadas sobre la línea media, ausencia de postfrontal y presencia de pie asimétrico. La familia Proterochampsidae se compone de cinco géneros presentes en las formaciones triásicas de Argentina y Brasil. En esta familia se incluye la especie argentina Proterochampsa barrionuevoi Reig, proveniente de la Formación Ischigualasto (Triásico Superior). Este taxón era conocido por el cráneo y algunas vértebras cervicales, pero el resto del material poscraneano era totalmente desconocido hasta el presente. En esta contribución se describe detalladamente un ejemplar de Proterochampsa barrionuevoi (PVSJ 606), incluyendo el cráneo, toda la serie vertebral, escápulas, coracoides, cintura pélvica, húmero derecho, radio y ulna del mismo lado, ambos fémures y miembro posterior derecho casi completo. Asimismo se presenta una diagnosis enmendada para la especie, constando de los siguientes caracteres neurocraneales diagnósticos: depresión semilunar expuesta ventrolateralmente, fosa basiesfenoidea rodeada rostrolateralmente por un reborde con forma de “V” con sus ramas convexas. Entre los caracteres que diferencian a P. barrionuevoi de la especie brasilera P. nodosa se citan: angostamiento anterior del hocico menos gradual que el de P. nodosa, occiput más deprimido, narinas lanceoladas con ambos extremos aguzados y frontal menos irregular que el de P. nodosa.

POSTCRANIAL MATERIAL OF PROTEROCHAMPSA BARRIONUEVOI REIG, 1959 (DIAPSIDA: ARCHOSAURIFORMES) FROM THE UPPER TRIASSIC OF CENTRAL-WESTERN ARGENTINA.

Abstract - Proterochampsids are members of the clade Archosauriformes, a group distinguished from others because of its depressed skulls transversely expanded at the posterior end, narrow and longitudinally long snout, nares located close to the midline, absence of postfrontals, and presence of an assymmetric pes. The family Proterochampsidae includes five genera recorded in Triassic formations of Argentina and Brazil. In this family is included the Argentinean species Proterochampsa barrionuevoi Reig, from the Late Triassic Ischigualasto Formation. This taxon was known from skulls and cervical vertebrae, but the rest of the postcranium remained unknown until now. Herein, a new and almost complete specimen of Proterochampsa barrionuevoi is described in detail (PVSJ 606). The specimen includes skull, complete vertebral series, scapulae, coracoids, pelvic girdle, right humerus, right radius and ulna, both femora, and complete right hindlimb. An emended diagnosis considering neurocranial features –semilunar depression ventrolaterally exposed, basisphenoidal fossa surround by a rostrolateraly V-shaped ridge with convex branches– is provided. The features distinguishing P. barrionuevoi from the Brazilian species P. nodosa are: snout becoming narrow anteriorly in a less gradual manner than in P. nodosa, lower occiput, nares lanceolate with narrow anterior and posterior ends, and frontal less irregular that in P. nodosa.

Oldest Known Dinosaurian Nesting Site

2012-01-24T13:33:00.001-07:00

Here is the abstract and link to the article discussed in the linked news report from yesterday.

Reisz, R. R., Evans, D. C., Roberts, E. M., Sues, H.-D., and A. M. Yates. 2012. Oldest known dinosaurian nesting site and reproductive biology of the Early Jurassic sauropodomorph Massospondylus. PNAS online before print. DOI 10.1073/pnas.1109385109

Abstract - The extensive Early Jurassic continental strata of southern Africa have yielded an exceptional record of dinosaurs that includes scores of partial to complete skeletons of the sauropodomorph Massospondylus, ranging from embryos to large adults. In 1976 an incomplete egg clutch including in ovo embryos of this dinosaur, the oldest known example in the fossil record, was collected from a road-cut talus, but its exact provenance was uncertain. An excavation program at the site started in 2006 has yielded multiple in situ egg clutches, documenting the oldest known dinosaurian nesting site, predating other similar sites by more than 100 million years. The presence of numerous clutches of eggs, some of which contain embryonic remains, in at least four distinct horizons within a small area, provides the earliest known evidence of complex reproductive behavior including site fidelity and colonial nesting in a terrestrial vertebrate. Thus, fossil and sedimentological evidence from this nesting site provides empirical data on reproductive strategies in early dinosaurs. A temporally calibrated optimization of dinosaurian reproductive biology not only demonstrates the primary significance of the Massospondylus nesting site, but also provides additional insights into the initial stages of the evolutionary history of dinosaurs, including evidence that deposition of eggs in a tightly organized single layer in a nest evolved independently from brooding.

Massospondylus Nesting Site from the Early Jurassic of South Africa

2012-01-23T20:01:00.000-07:00

http://www.cbc.ca/news/technology/story/2012/01/23/sci-dinosaur-nesting-site.html

Aetobarbakinoides brasiliensis, a New Aetosaur from the Late Triassic of Brazil

2012-01-19T09:05:00.000-07:00

This is an interesting new specimen from the Santa Maria Formation of Brazil. I've had the chance to personally study this material and although poorly preserved and despite possesses a radial patterning of the dorsal osteoderms it clearly does not belong to the South American genera Aetosauroides or Neoaetosauroides mainly because of characteristics of the vertebrae. In fact, the vertebrae with their well developed accessory processes and lack of ventral keels strongly resemble those of desmatosuchines. This is supported by the phylogenetic analysis.

Notably this is the first aetosaur taxon to be diagnosed using postcranial characters rather than those of the osteoderms. Indeed only a few poorly preserved osteoderms are present in the specimen. I've argued in the past that despite the long use of armor ornamentation to diagnose aetosaur species, new specimens are demonstrating that these characters are highly convergent between hypothesized main aetosaur clades and caution must be used.

This paper also finds Aetosaurinae (sensu Parker, 2007) to be paraphyletic. Again this is not surprising given the poor support for the clade in the original analysis, the fact that Aetobarbakinoides possesses "Aetosaurinae"-like armor with desmatosuchine-like vertebrae, and the fact that lateral armor is lacking in this new taxon whereas lateral armor characters strongly affect the topology of Parker (2007). This is not surprising given that the analysis of Parker (2007) was explicitly testing the phylogenetic signal of lateral osteoderms in aetosaurs.

This analysis also recovers Aetosauroides outside of Stagonolepididiae (sensu Heckert and Lucas, 2000), which demonstrates the presence of non-stagonolepidid aetosaurs. Thus the names Stagonolepididae and Aetosauria cannot be used interchangeably (as they commonly are) as I cautioned in 2007.

There is much more work today with the phylogeny of the Aetosauria and many new undescribed specimens. I am focusing on a lot of these in my ongoing PhD work.

Desojo, J. B., Ezcurra, M. D., and E. E. Kischlat. 2012. A new aetosaur genus (Archosauria: Pseudosuchia) from the early Late Triassic of southern Brazil. Zootaxa 3166:1-33.

Abstract - We describe the new aetosaur Aetobarbakinoides brasiliensis gen. et sp. nov. from the early Late Triassic (late Carnian early Norian) Brazilian Santa Maria Formation. The holotype is composed of a partial postcranium including several cervical and dorsal vertebrae and ribs, one anterior caudal vertebra, right scapula, right humerus, right tibia, partial right pes, and anterior and mid-dorsal paramedian osteoderms. Aetobarbakinoides is differentiated from other aetosaurs by the presence of cervical vertebrae with widely laterally extended prezygapophyses, mid-cervical vertebrae with anterior articular facet width more than 1.2 times wider than the posterior one, anterior caudal vertebrae with extremely anteroposteriorly short prezygapophyses, elongated humerus and tibia in relation to the axial skeleton, and paramedian osteoderms with a weakly raised anterior bar. A cladistic analysis recovered the new species as more derived than the South American genera Aetosauroides (late Carnian-early Norian) and Neoaetosauroides (late Norian-Rhaetian), and it is nested as the sister-taxon of an unnamed clade, composed of Typothoracisinae and Desmatosuchinae, due to the absence of a ventral keel in the cervical vertebrae. Aetobarbakinoides presents a skeletal anatomy previously unknown among South American aetosaurs, with the combination of presacral vertebrae with hyposphene, anteroposteriorly short and unkeeled cervical vertebrae, gracile limbs, and paramedian osteoderms with a weakly raised anterior bar. Aetobarbakinoides is among the oldest known aetosaurs together with Aetosauroides from Argentina and Brazil and Stagonolepis robertsoni from Scotland, indicating Aetobarbakinoides, which is one of the oldest known aetosaurs, is in agreement with an older origin for the group, as it is expected by the extensive ghost lineages at the base of the main pseudosuchian clades.

Evolution of Bipedality and Herbivory Among Triassic Dinosauromorphs

2012-01-18T20:51:00.001-07:00

Note that this paper is in Japanese with an English version of the abstract.

Kubo, T. 2011. Evolution of bipedality and herbivory among Triassic dinosauromorphs. Memoir of the Fukui Prefectural Dinosaur Museum 10:55－62．

Abstract - Discoveries of Triassic non-dinosaur dinosauromorphs since 2000 revealed that they were more widely spread chronologically and geographically than previously thought. A member of silesaurids, the sister clade of dinosaurs, Silesaurus was a quadrupedal and herbivorous animal that differs considerably from the condition previously assumed for the ancestor of dinosaurs that are bipedal and carnivorous. Currently, stance and diet of the common ancestor of dinosaurs are not clear. To redeem this situation, Ancestral State Reconstruction methods were conducted to infer how quadrupedality and herbivory were evolved among dinosauromorphs. The results of analyses indicate that quadrupedal stance evolved only among silesaurids. Herbivorous diet was readily evolved from carnivorous diet among Dinosauromorpha and the ancestral state reconstruction using likelihood methods indicated that the possibility of the common ancestor of dinosaurs being herbivore is more than 60%.

Two New Triassic Temnospondyl Papers in the Journal Palaeontology

2012-01-10T19:48:00.001-07:00

Witzmann, F., Schoch, R. R., Hilger, A., and N. Kardjilov. 2012. Braincase, palatoquadrate and ear region of the plagiosaurid Gerrothorax pulcherrimus from the Middle Triassic of Germany. Palaeontology 55:31-50. DOI: 10.1111/j.1475-4983.2011.01116.x

Abstract - The complete neurocranium plus palatoquadrate of the plagiosaurid temnospondyl Gerrothorax pulcherrimus from the Middle Triassic of Germany is described for the first time, based on outer morphological observations and micro-CT scanning. The exoccipitals are strong elements with paroccipital processes and well-separated occipital condyles. Anterolaterally, the exoccipitals contact the otics, which are mediolaterally elongated and have massive lateral walls. The otics contact the basisphenoid, which shows well-developed sellar processes. Anteriorly, the basisphenoid is continuous with the sphenethmoid region. In its posterior portion, the sphenethmoid gives rise to robust, laterally directed laterosphenoid walls, a unique morphology among basal tetrapods. The palatoquadrate is extensively ossified. The quadrate portion overlaps the descending lamina of squamosal and ascending lamina of pterygoid anteriorly, almost contacting the epipterygoid laterally. The epipterygoid is a complex element and may be co-ossified with otics and laterosphenoid walls. It has a broad, sheet-like footplate and a horizontally aligned ascending process that contacts the laterosphenoid walls. The degree of ossification of the epipterygoid, however, is subject to individual variation obviously independent from ontogenetic changes. The stapes of Gerrothorax is a large, blade-like element that differs conspicuously from the plesiomorphic temnospondyl condition. It has a prominent anterolateral projection which has not been observed in other basal tetrapods. Morphology of neurocranium and palatoquadratum of Gerrothorax most closely resembles that of the Russian plagiosaurid Plagiosternum danilovi, although the elements are less ossified in the latter. The extensive endocranial ossification of Gerrothorax is consistent with the general high degree of ossification in the exo- and endoskeleton of this temnospondyl and supports the view that a strong endocranial ossification cannot be evaluated as a plesiomorphic character in basal tetrapods.

Dias-da-Silva, S., Sengupta, D. P., Cabriera, S. F., and L. R. Da Silva. 2012. The presence of Compsocerops (Brachyopoidea: Chigutisauridae) (Late Triassic) in southern Brazil with comments on chigutisaurid palaeobiogeography. Palaeontology 55:163-172. DOI: 10.1111/j.1475-4983.2011.01120.x

Abstract - Chigutisauridae is the longest-lived trematosaurian clade (from early Triassic to early Cretaceous). They were reported in Argentina, Australia, India and South Africa. This contribution reports a putative chigutisaurid specimen in the Carnian of southern Brazil (Santa Maria Formation, Paraná Basin). The material comprises two skull fragments, a mandibular fragment, a clavicular blade and a humerus. Ontogenetic features point to an early development stage of the specimen. The presence of a long, straight and pointed tabular horn, which runs parallel to the skull midline towards its tip, and a distinctive projection in the posterior border of the postparietal indicates a close relationship of the Brazilian chigutisaurid with the Indian Compsocerops cosgriffi. Three distinctive and combined characters suggest that the Brazilian chigutisaurid is a distinctive specimen: the presence of an alar process of the jugal in the ventral margin of the orbit; jugal does not extend well beyond the anterior margin of the orbit; and tabular does not contact the parietal. These characters could justify the erection of a new taxon; however, they might reflect its immature ontogenetic stage as well. Accordingly, we attribute this new specimen to Compsocerops sp. Argentinean and Indian occurrences are dated as Norian, so the presence of a Carnian chigutisaurid in southern Brazil indicates that western Gondwana chigutisaurids have first occupied the Paraná Basin and later migrated towards west (to Argentina) and east (India). However, the presence of ghost chigutisaurid taxa cannot be dismissed, because their long temporal range contrasts with their still short (in comparison with other temnospondyl groups) geographic distribution. Hence, they might have been more geographically widespread than their fossil record suggests.

Revisiting the Cranial Anatomy of the Thalattosaur Anshunsaurus huangnihensis

2011-12-28T15:32:00.000-07:00

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.

Happy Holidays!

2011-12-24T11:42:00.000-07:00

HAPPY HOLIDAYS FROM CHINLEANA!

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

2011-12-23T11:24:00.000-07:00

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!

2011-12-20T15:52:00.000-07:00

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

2011-12-19T19:59:00.002-07:00

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

2011-12-15T14:54:00.002-07:00

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

2011-12-14T10:20:00.003-07:00

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

2011-12-10T21:56:00.001-07:00

The following blurb is from http://uncyclopedia.wikia.com/wiki/Archaeologist#Archaeologists_VS_Paleontologists

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

2011-12-05T21:38:00.001-07:00

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

2011-12-02T16:30:00.000-07:00

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

2011-12-02T08:00:00.000-07:00

You can read it here:

http://www.economist.com/node/21540979

Triassic palaeontology in the Economist.

Braincase of the Temnospondyl Gerrothorax from the Middle Triassic of Germany

2011-11-28T12:00:00.000-07:00

Witzmann, F., Schoch, R. R., Hilger, A. and N. Kardjilov. 2011. Braincase, palatoquadrate and ear region of the plagiosaurid Gerrothorax pulcherrimus from the Middle Triassic of Germany. Palaeontology (early online). doi: 10.1111/j.1475-4983.2011.01116.x

Abstract - The complete neurocranium plus palatoquadrate of the plagiosaurid temnospondyl Gerrothorax pulcherrimus from the Middle Triassic of Germany is described for the first time, based on outer morphological observations and micro-CT scanning. The exoccipitals are strong elements with paroccipital processes and well-separated occipital condyles. Anterolaterally, the exoccipitals contact the otics, which are mediolaterally elongated and have massive lateral walls. The otics contact the basisphenoid, which shows well-developed sellar processes. Anteriorly, the basisphenoid is continuous with the sphenethmoid region. In its posterior portion, the sphenethmoid gives rise to robust, laterally directed laterosphenoid walls, a unique morphology among basal tetrapods. The palatoquadrate is extensively ossified. The quadrate portion overlaps the descending lamina of squamosal and ascending lamina of pterygoid anteriorly, almost contacting the epipterygoid laterally. The epipterygoid is a complex element and may be co-ossified with otics and laterosphenoid walls. It has a broad, sheet-like footplate and a horizontally aligned ascending process that contacts the laterosphenoid walls. The degree of ossification of the epipterygoid, however, is subject to individual variation obviously independent from ontogenetic changes. The stapes of Gerrothorax is a large, blade-like element that differs conspicuously from the plesiomorphic temnospondyl condition. It has a prominent anterolateral projection which has not been observed in other basal tetrapods. Morphology of neurocranium and palatoquadratum of Gerrothorax most closely resembles that of the Russian plagiosaurid Plagiosternum danilovi, although the elements are less ossified in the latter. The extensive endocranial ossification of Gerrothorax is consistent with the general high degree of ossification in the exo- and endoskeleton of this temnospondyl and supports the view that a strong endocranial ossification cannot be evaluated as a plesiomorphic character in basal tetrapods.

Disparity and Convergence in Bipedal Archosaur Locomotion

2011-11-25T11:32:00.001-07:00

Bates, K. T., and E. R. Schachner. 2011. Disparity and convergence in bipedal archosaur locomotion. Journal of the Royal Society Interface (advance online publication) doi: 10.1098/rsif.2011.0687

Abstract - This study aims to investigate functional disparity in the locomotor apparatus of bipedal archosaurs. We use reconstructions of hindlimb myology of extant and extinct archosaurs to generate musculoskeletal biomechanical models to test hypothesized convergence between bipedal crocodile-line archosaurs and dinosaurs. Quantitative comparison of muscle leverage supports the inference that bipedal crocodile-line archosaurs and non-avian theropods had highly convergent hindlimb myology, suggesting similar muscular mechanics and neuromuscular control of locomotion. While these groups independently evolved similar musculoskeletal solutions to the challenges of parasagittally erect bipedalism, differences also clearly exist, particularly the distinct hip and crurotarsal ankle morphology characteristic of many pseudosuchian archosaurs. Furthermore, comparative analyses of muscle design in extant archosaurs reveal that muscular parameters such as size and architecture are more highly adapted or optimized for habitual locomotion than moment arms. The importance of these aspects of muscle design, which are not directly retrievable from fossils, warns against over-extrapolating the functional significance of anatomical convergences. Nevertheless, links identified between posture, muscle moments and neural control in archosaur locomotion suggest that functional interpretations of osteological changes in limb anatomy traditionally linked to postural evolution in Late Triassic archosaurs could be constrained through musculoskeletal modelling.

New Material of the Cynodont Dadadon isaloi from the Triassic of Madagascar

2011-11-23T15:00:00.000-07:00

Ranivoharimanana, L., Kammerer, C. F., John J. Flynn, J. J., and A. R. Wyss. 2011. New material of

Abstract - New material of the traversodontid cynodont Dadadon isaloi from the Triassic of southwestern Madagascar is described. The new material consists of a complete, well-preserved skull (FMNH PR 2232) and an unassociated, partial lower jaw (UA 10608). The new material reveals several novel aspects of Dadadon's morphology. Newly recognized autapomorphies that diagnose Dadadon include a fourth upper incisor with posterior accessory cusp, deep interorbital depressions confined to the frontals, and a very tall, robust mid-frontal ridge. Dadadon can further be distinguished from the similar traversodontids Massetognathus and Santacruzodon by the presence of shorter, broader prefrontals with prominent dorsal depressions, robust anterolateral processes overhanging the orbits, a single cusp in the anterior cingulum of the upper postcanines, and relatively elongate, striated, conical upper incisors. In a revised phylogenetic analysis incorporating data from the new specimens, Dadadon is recovered in a clade with Massetognathus and Santacruzodon. This clade is the sister taxon to the well-supported traversodontid subclade Gomphodontosuchinae. The ‘basal Isalo II’ cynodont fauna from Madagascar is more similar in composition to that of South America than to mainland Africa, although this is probably attributable to the lack of Ladinian–Carnian therapsid fossils on the mainland rather than an actual biogeographic pattern.

Dadadon isaloi (Cynodontia, Traversodontidae) from the Triassic of Madagascar. Journal of Vertebrate Paleontology 31:1292-1302. DOI:10.1080/02724634.2011.618154

Osteohistology of Some Triassic Archosauromorphs

2011-11-22T21:15:00.001-07:00

Botha-Brink, J., and R. M. H. Smith. 2011. Osteohistology of the Triassic archosauromorphs Prolacerta, Proterosuchus, Euparkeria, and Erythrosuchus from the Karoo Basin of South Africa. Journal of Vertebrate Paleontology 31:1238-1254. DOI:10.1080/02724634.2011.621797

Abstract - The South African non-archosauriform archosauromorph Prolacerta and the archosauriforms Proterosuchus, Erythrosuchus, and Euparkeria were important constituents of the Early to early Middle Triassic Karoo ecosystem following the end-Permian mass extinction. We present new data on the osteohistology of these stem archosaurs and provide insight into their paleobiology. Bone tissues of the Early Triassic Prolacerta contain a poorly defined fibro-lamellar complex, with parallel-fibered bone in some regions, whereas the contemporaneous Proterosuchus exhibits rapidly forming uninterrupted fibro-lamellar bone early in its ontogeny, which becomes slow forming lamellar-zonal bone with increasing age. The early Middle Triassic Erythrosuchus deposited highly vascularized, uninterrupted fibro-lamellar bone throughout ontogeny, whereas the growth of the contemporaneous Euparkeria was relatively slow and cyclical. When our data are combined with those of previous studies, preliminary results reveal that Early and Middle Triassic non-crown group archosauromorphs generally exhibit faster growth rates than many of those of the Late Triassic. Early rapid growth and rapid attainment of sexual maturity are consistent with life history expectations for taxa living in the unpredictable conditions following the end-Permian mass extinction. Further research with larger sample sizes will be required to determine the nature of the environmental pressures on these basal archosaurs.

Redescription of a Nearly Complete Skull of Plateosaurus from the Late Triassic of Germany

2011-11-21T21:35:00.001-07:00

Prieto-Márquez, A., and M. A. Norell. 2011. Redescription of a nearly complete skull of Plateosaurus (Dinosauria: Sauropodomorpha) from the Late Triassic of Trossingen (Germany). American Museum Novitates 3727 :1-58.
doi: http://www.bioone.org/doi/abs/10.1206/3727.2

Abstract - The nearly complete, disarticulated skull of AMNH FARB 6810, a specimen of the basal sauropodomorph Plateosaurus collected in 1925 from the Norian (Late Triassic) strata of the Knollenmergel beds of Trossingen (Germany), is redescribed. This study supports referral of AMNH FARB 6810 to P. erlenbergiensis on the basis of the following characters: occipital condyle above level of parasphenoid; basisphenoid with transverse, subvertical lamina extending between basipterygoid processes, with ventrally projecting median process; and peglike process projecting medially from the middle of the palatine. Furthermore, P. longiceps is regarded a junior synonym of P. erlenbergiensis because the type specimen of the latter is diagnostic (displaying the above-noted apomorphies of the braincase and palatine) and, chronologically, P. erlenbergiensis has priority over P. longiceps.

Did An Extraterrestrial Impact Hasten the End-Triassic Extinction On Land?

2011-11-17T12:00:00.000-07:00

This is a interesting news article in Nature examining work by Drs. Paul Olsen and Dennis Kent on the possibility that the Rochechouart impact in France may have had an adverse effect on global terrestrial populations around 200 million years ago. The article also includes an excellent new Triassic scene by Victor O. Leshyk, which features Redondavenator and Redondasaurus from the Upper Triassic Redonda Formation of New Mexico. There is also a Typothorax-like aetosaur in the background for armodillodile fans.

Pampadromaeus barberenai, a New Basal Sauropodomorph from the Late Triassic of Brazil

2011-11-16T20:13:00.001-07:00

For those of you who were at SVP this year, this is the new dinosaur taxon from the Triassic of Brazil that Max Langer presented on.

Cabreira, S. F., Schultz, C. L., Bittencourt, J. S., Soares, M. B., Fortier, D. C., Silva, L. R., and M. C. Langer. 2011. New stem-sauropodomorph (Dinosauria, Saurischia) from the Triassic of Brazil. Naturwissenschaften (advance online publication) DOI: 10.1007/s00114-011-0858-0

Abstract - Post-Triassic theropod, sauropodomorph, and ornithischian dinosaurs are readily recognized based on the set of traits that typically characterize each of these groups. On the contrary, most of the early members of those lineages lack such specializations, but share a range of generalized traits also seen in more basal dinosauromorphs. Here, we report on a new Late Triassic dinosaur from the Santa Maria Formation of Rio Grande do Sul, southern Brazil. The specimen comprises the disarticulated partial skeleton of a single individual, including most of the skull bones. Based on four phylogenetic analyses, the new dinosaur fits consistently on the sauropodomorph stem, but lacks several typical features of sauropodomorphs, showing dinosaur plesiomorphies together with some neotheropod traits. This is not an exception among basal dinosaurs, the early radiation of which is characterized by a mosaic pattern of character acquisition, resulting in the uncertain phylogenetic placement of various early members of the group.