Rastodon procurvidens: a new Guadalupian/Lopingian Permian Dicynodont From Brazil

A New Dicynodont (Therapsida: Anomodontia) from the Permian of Southern Brazil and Its Implications for Bidentalian Origins

Authors:

Boos et al

Abstract:

Dicynodonts were a highly successful group of herbivorous therapsids that inhabited terrestrial ecosystems from the Middle Permian through the end of the Triassic periods. Permian dicynodonts are extremely abundant in African deposits, but are comparatively poorly known from the other regions of Gondwana. Here we describe a new South American dicynodont, Rastodon procurvidens gen. et sp. nov., from the Boqueirão farm site of the Rio do Rasto Formation, Paraná Basin, Guadalupian/Lopingian of Brazil. Diagnostic features of R. procurvidens include uniquely anteriorly-curved maxillary tusks, well-developed ridges extending from the crista oesophagea anteriorly along the pterygoid rami, strong posterior angulation of the posterior pterygoid rami, and a bulbous, well-developed retroarticular process of the articular. Phylogenetic analysis indicates that R. procurvidens is the earliest and most basal member of Bidentalia, a cosmopolitan clade that includes Permian and Triassic dicynodonts whose dentition is usually reduced to a pair of maxillary tusks.

Lystrosaurus LIved Fast, Died Young After Permian Extinction

Two hundred and fifty-two million years ago, a series of Siberian volcanoes erupted and sent the Earth into the greatest mass extinction of all time. As a result of this mass extinction, known as the Permo-Triassic Mass Extinction, billions of tons of carbon were propelled into the atmosphere, radically altering the Earth's climate. Yet, some animals thrived in the aftermath and scientists now know why.

In a new study published in Scientific Reports, a team of international paleontologists, including postdoctoral scholar Adam Huttenlocker of the Natural History Museum of Utah at the University of Utah, demonstrate that ancient mammal relatives known as therapsids were suited to the drastic climate change by having shorter life expectancies and would have had a better chance of success by breeding at younger ages than their predecessors.

The research team studied growth patterns in therapsids from the South African Karoo Basin, a paleontologically significant area which preserves a wide range of fossils from the Permian to the Early Jurassic, or 300-180 million years ago.

By examining their bone microstructure before and after the extinction boundary, Huttenlocker and his colleagues were able to study how growth patterns in therapsids were affected by the extinction. By studying body size distributions in particularly abundant species from the Permian and Triassic, the team was able to interpret shifts in size class structure and in rates of survivorship.

"Therapsid fossils like Lystrosaurus are important because they teach us about the resilience of our own extinct relatives in the face of extinction, and provide clues to which traits confered success on lineages during this tubulent time. Lystrosaurus was particularly prolific, making it possible to build a large dataset and to sacrifice some specimens for histology to study the growth patterns recorded in its bones," said Huttenlocker, one of the paper's authors.

"Before the Permo-Triassic extinction, the famous therapsid Lystrosaurus had a life span of about 13 or 14 years based on the record of growth preserved in their bones," said Field Museum paleontologist Ken Angielczyk, another one of the paper's authors. "Yet, nearly all of the Lystrosaurus specimens we find from after the extinction are only 2¬-3 years old. This implies that they must have been breeding when they were still [relatively young] themselves."

This adjustment in life history also meant a physical change for Lystrosaurus. Before the mass extinction, this creature would have been a couple meters long and weighed hundreds of pounds—about the size of a pygmy hippo. Post-extinction, its size dropped to that of a large dog, in large part due to its altered lifespan. Yet, these adaptations seemed to pay off for Lystrosaurus. Ecological simulations show that by breeding younger, Lystrosaurus could have increased its chance of survival by 40% in the unpredictable environments that existed in the aftermath of the extinction.

link.

here, here and here, too.

Middle Permian Dicynodont Chelydontops altidentalis is a Junior Synonym of Brachyprosopus broomi

A reevaluation of Brachyprosopus broomi and Chelydontops altidentalis, dicynodonts (Therapsida, Anomodontia) from the middle Permian Tapinocephalus Assemblage Zone of the Karoo Basin, South Africa

Authors:

Angielczyk et al

Abstract:

Brachyprosopus broomi was described in 1937 based on a specimen from the Tapinocephalus Assemblage Zone (Karoo Basin, South Africa), but it was largely overlooked by subsequent workers. We have identified several new specimens that show that Brachyprosopus is a valid taxon. An autapomorphy for the taxon is a curled lateral edge of the squamosal that forms a lateral wall of the external adductor fossa. Other important characters are absence of anterior median palatal ridges; maxillary tooth rows bounded laterally by a shelf; unfused vomers; raised margins of the interpterygoid vacuity; broad intertemporal region; pineal boss; dentary tables; and a long, wide posterior dentary sulcus that extends posterior to the dentary teeth. Chelydontops altidentalis is a junior synonym of B. broomi. A phylogenetic analysis places Brachyprosopus among basal dicynodonts, not as a close relative of Endothiodon. It is noteworthy that some characters, such as well-developed medial maxillary tooth rows and the shape of the palatines, are shared by Brachyprosopus, Pristerodon, Endothiodon, and Niassodon, hinting that a final resolution of relationships among toothed dicynodonts remains to be achieved. Most Brachyprosopus specimens are from the upper Abrahamskraal Formation (Moordenaars and Karelskraal members). One specimen is from low in the Koonap Formation, just above the lowermost maroon mudrocks of the Beaufort Group, and an exact correlation between this level and the strata of the Abrahamskraal Formation is uncertain. Therefore, it is likely that the stratigraphic range of Brachyprosopus extends throughout the Tapinocephalus zone and possibly down into the Eodicynodon Assemblage Zone.

A new Emydopoid Dicynodont From Upper Permian Tanzania

Distinctive emydopoid dicynodont (Therapsida, Anomodontia) mandibles from the Permian Ruhuhu and Usili formations (Songea Group), Ruhuhu Basin, Tanzania

Authors:

Angielczyk et al

Abstract:

Dicynodont therapsids were discovered in the Permian Usili Formation (Ruhuhu Basin, Tanzania) in the 1930s and in the Permian Ruhuhu Formation in the 1960s, with further collections being made in 2007, 2008, and 2012. Here we describe two fragmentary mandibles that represent a new morphotype of emydopoid dicynodont. One specimen was collected in the middle fossiliferous horizon of the Ruhuhu Formation, and the other originated in the overlying Usili Formation. Three synapomorphies support the placement of these specimens in the emydopoid subclade Kingoriidae: mandibular fenestra occluded by the dentary; curved ridge that follows the profile of the symphysis present on the edge between the anterior and lateral surfaces of the dentary; and posterior dentary sulcus absent. The specimens may represent a new dicynodont species, a previously known species for which mandibular material was unknown, or an intraspecific variant of Dicynodontoides nowacki. Regardless of which of these options is correct, the specimens constitute the first taxon with a stratigraphic range extending from the likely middle Permian middle fossiliferous horizon of the Ruhuhu Formation into the late Permian Usili Formation. They also improve our understanding of the middle Ruhuhu tetrapod fauna, which previously consisted only of Endothiodon tolani.

Intraspecies Combat Probably Practiced by Roadian Permian Anomodonts Tiarajudens & Anomocephalus

Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana

Authors:

Cisneros et al

Abstract:

Anomodontia was a highly successful tetrapod clade during the Permian and the Triassic. New morphological information regarding two bizarre basal anomodonts is provided and their palaeoecological significance is explored. The osteology of the recently discovered Tiarajudens eccentricus Cisneros et al. 2011, from the Brazilian Permian, is described in detail. The taxon exhibits unusual postcranial features, including the presence of gastralia. Additional preparation and computed tomography scans of the holotype of Anomocephalus africanus Modesto et al. 1999 discovered in the Karoo Basin of South Africa allow a reappraisal of this genus. Anomocephalus is similar to Tiarajudens with regard to several traits, including a battery of large, transversally expanded, palatal teeth. Molariform teeth are present in the mandible of the African taxon, providing additional insight into the function of the earliest tooth-occlusion mechanism known in therapsids. At least two waves of tooth replacement can be recognized in the palate of Anomocephalus. The outsized, blade-like caniniforms of the herbivorous Tiarajudens allow several non-exclusive ecological interpretations, among which we favour intraspecific display or combat. This behaviour was an alternative to the head-butting practised by the contemporary dinocephalians. Combat specializations that are considered typical of Cenozoic herbivores likely evolved during the Middle Permian, at the time the first communities with diverse, abundant tetrapod herbivores were being assembled.

Emydopoid Dicynodont Digalodon rubidgei Redescribed

Redescription of Digalodon rubidgei, an emydopoid dicynodont (Therapsida, Anomodontia) from the Late Permian of South Africa. (pdf)

Authors:

Fröbisch et al

Abstract:

The Late Permian dicynodont Digalodon rubidgei Broom and Robinson, 1948, is redescribed based on reanalysis of the holotype and newly recognized referable specimens. Digalodon can be diagnosed by the presence of a long “beak” sharply demarcated from the caniniform process; an extremely tall zygomatic ramus of the squamosal, with a thickened, “folded-over” dorsal margin; raised parietal “lips” along the lateral edges of the pineal foramen; and a broad posterolateral expansion of the parietal, excluding the postorbital from the back of the skull roof. Inclusion of Digalodon in a recent analysis of anomodont phylogeny recovers it as a kistecephalian emydopoid, specifically as the sister taxon to the clade containing the remaining kistecephalians. Four definite specimens of Digalodon are known, but several additional specimens lacking tusks, the swollen pineal “lips”, and a thickened zygoma may represent sexually dimorphic females or juveniles. Specimens of Digalodon are restricted to the central portion of the Karoo Basin, in the area around Graaff-Reinet, and are part of a characteristic fauna probably representing a limited time span.

New Kannemeyeriiforme Dicynodonts From Middle Triassic China

New discoveries from the Sinokannemeyeria-Shansisuchus Assemblage Zone: 1. Kannemeyeriiformes from Shanxi, China

Author:

Jun

Abstract:

Recently, some new tetrapod fossils were collected along the Yellow River in Shanxi Province. From the Member I of the Tongchuan Formation at Baidaoyu in Linxian County, at least one species of Parakannemeyeria, and one new species of Sinokannemeyeria, S. baidaoyuensis, are identified. The new species is characterized by prefrontal anterior extension level to posterior margin of postnarial excavation. From the Ermaying Formation in Liulin County, a third kannemeyeriid genus is identified for the Sinokannemeyeria-Shansisuchus Assemblage. The new findings increase the content and time extension of the Sinokannemeyeria-Shansisuchus Assemblage.

How Well Late Permian, Burrowing Anomodont Kawingasaurus Felt Vibrations and Sounds

Bone-conduction hearing and seismic sensitivity of the late permian anomodont Kawingasaurus fossilis

Author:

Laaß

Abstract:

An investigation of the internal cranial anatomy of the anomodont Kawingasaurus from the Upper Permian Usili Formation in Tanzania by means of neutron tomography revealed an unusual inner and middle ear anatomy such as extraordinarily inflated vestibules, lateroventrally orientated stapes with large footplates, and a small angle between the planes of the anterior and lateral semicircular canals. The vestibule has a volume, which is about 25 times larger than the human vestibule, although Kawingasaurus has only a skull length of approximately 40 mm. Vestibule inflation and enlarged stapes footplates are thought to be functionally correlated with bone-conduction hearing; both morphologies have been observed in fossorial vertebrates using seismic signals for communication. The firmly fused triangular head with spatulate snout was probably used for digging and preadapted to seismic signal detection. The quadrate-quadratojugal complex was able to transmit sound from the articular to the stapes by small vibrations of the quadrate process, which formed a ball and socket joint with the squamosal. Mechanical considerations suggest that the ventrolaterally orientated stapes of Kawingasaurus was mechanically better suited to transmit seismic sound from the ground to the fenestra vestibuli than a horizontal orientated stapes. The low sound pressure level transformer ratio of 2–3 in Kawingasaurus points to a seismic sensitivity of the middle ear and a vestigial or reduced sensitivity to airborne sound. Three hypothetical pathways of bone conduction in Kawingasaurus are discussed: 1) sound transmission via the spatulate snout and skull roof to the otic capsules, 2) relative movements resulting from the inertia of the mandible if sound is percepted with the skull, and 3) bone conduction from the substrate via mandible, jaw articulation, and stapes to the inner ear.

Sungeodon kimkraemerae: a Kannemeyeriiform Dicynodont From Earliest Triassic China

Sungeodon kimkraemerae n. gen. n. sp., the oldest kannemeyeriiform (Therapsida, Dicynodontia) and its implications for the early diversification of large herbivores after the P/T boundary

Authors:

Maisch et al

Abstract:

The dicynodont Sungeodon kimkraemerae n. gen. n. sp. is described on the basis of a skull from the Lower Triassic Jiucaiyuan Formation of Dalongkou (Junggar Basin, Xinjiang Uygur Autonomous Region, People's Republic of China). It is the first representative of Kannemeyeriiformes from the earliest Triassic. Kannemeyeriiforms were the predominant clade of Triassic dicynodonts, which constituted a major component of terrestrial Triassic ecosystems. The new taxon helps closing one of the most significant gaps in the fossil record of dicynodonts, since stem-kannemeyeriiforms are known from the Late Permian, whereas the first true kannemeyeriiforms previously known are late Early Triassic in age. After a phylogenetic analysis Sungeodon belongs to the family Stahleckeriidae. Therefore, the Stahleckeriidae may not have had its origin in Africa as previously assumed, but in Central Asia. More importantly, Sungeodon also suggests that the major radiation of kannemeyeriiform dicynodonts, including the emergence of all relevant subgroups of this clade, occurred not later than in the Early Triassic, soon after the end-Permian extinction. To date, only few dicynodont taxa are known from the earliest Triassic, none of which are kannemeyeriiforms. The addition of Sungeodon confirms previous predictions that our knowledge of Early Triassic dicynodont diversity and evolution is far from being complete, and that new discoveries from historically low-sampled geographic regions may fill this gap. A rapid post-extinction diversification of kannemeyeriiforms also fits with the emerging picture from other clades, such as archosaurs, of a rapid recovery from the end-Permian event in the terrestrial realm.

Completeness and Quality of the Fossil Record of Anomodonts

The quality of the fossil record of anomodonts (Synapsida, Therapsida)

Authors:

Marcus Walther and Jörg Fröbisch

Abstract:

The quality of the fossil record of anomodont synapsids, one of the major clades of Permian–Triassic terrestrial tetrapods, is assessed. A Character Completeness Metric (CCM2) is calculated for each taxon and consecutive time intervals at a global scale and in the South African Karoo Basin. The mean completeness score is 66.80% (globally) and 77.37% (regionally) with completeness ranging between 60.12% and 91.33% per time interval. Up-to-date taxic, phylogenetic and residual diversity estimates confirm the general biodiversity trends recovered by recent analyses. The consistently high CCM2 scores throughout their evolutionary history together with a lack of correlation with biodiversity patterns and sampling proxies document a high quality of the known anomodont fossil record. In fact, when compared to other vertebrate groups, the completeness values for anomodonts are exceptionally high. Yet, whether this pattern results from the unrivalled record of the Karoo Basin or whether it is clade-specific and unique to anomodonts remains to be tested.

Lystrosaurus Subadults Were Trying to Keep Warm When They Died Creating Bonebeds in Induan (?) Triassic South Africa

Origin and palaeoenvironmental significance of Lystrosaurus bonebeds in the earliest Triassic Karoo Basin, South Africa

Authors:

Pia A. Viglietti, Roger M.H. Smith, and John S. Compton

Affiliations:

Earth experienced its most devastating extinction event at the end of the Permian period 251 million years ago (Ma). Despite an estimated 75 to 90% loss of species globally in both marine and terrestrial realms across the Permian–Triassic Boundary (PTB), around 20% of the terrestrial tetrapod genera in southwestern Gondwana survived and were immediately joined by a number of immigrant taxa to occupy most of the vacant niches of the earliest Triassic. Preserved in the Karoo Basin of South Africa is an almost continuous stratigraphic record of terrestrial sedimentation through the PTB that hosts a fossil record of ecosystem collapse, survivorship and recovery. The adaptation of the mammal like reptiles (therapsids) of the Lystrosaurus Assemblage Zone to a highly seasonal, potentially drought prone semi-arid earliest Triassic Karoo Basin is associated with changes in modes of fossilisation. Isolated dicynodont skulls and postcranial elements are commonly found in the latest Permian. However, in the earliest Triassic the dicynodonts occur as articulated, curled-up skeletons and multi-individual monotaxic bonebeds. Lack of epiphyses and relatively small skull length confirm that the bonebeds comprise several subadult Lystrosaurus declivis (L. declivis) carcasses. No significant evidence for hydraulic bone concentration along with clusters of ribs in life position points to complete carcasses being present at the site of death, and suggests that animals behaviourally congregated before perishing together. The bonebeds are hosted by an 8 m thick horizon of floodplain mudrocks in the lower Katberg Formation named the Lystrosaurus abundant zone. The bonebed horizon is overlain by sand-filled mud cracks capped by coarse sediments indicative of rapid deposition during waning floods. Stable isotope analyses of pedogenic and early diagenetic calcite nodules in association with the bonebeds yield average δ13C values ranging from − 9.5 to − 5‰ and δ18O values of 13.5 to 16‰, respectively. These isotope values support a seasonally cold, semi-arid climate at high latitude (~ 55°S). The presence of vertebrate burrow casts on bonebed horizons and evidence of shelter sharing suggests that tetrapods were attempting to escape extreme climatic conditions. Aggregation behaviour of subadult Lystrosaurus during unusual cold snaps may best explain the origin of bonebed assemblages.

Scythian Triassic Lystrosaurus Bonebed Origins and Implications

Origin and palaeoenvironmental significance of Lystrosaurus bonebeds in the earliest Triassic Karoo Basin, South Africa

Authors:

1. Pia A. Viglietti (a)
2. Roger M.H. Smith (b)
3. John S. Compton (a)

Affiliations:

a. Department of Geological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, (+ 27733760065)

b. Iziko South African Museum of Cape Town, P.O. Box 61, Cape Town, 8000 South Africa

Abstract:

Earth experienced its most devastating extinction event at the end of the Permian period 251 million years ago (Ma). Despite an estimated 75 to 90% loss of species globally in both marine and terrestrial realms across the Permian–Triassic Boundary (PTB), around 20% of the terrestrial tetrapod genera in southwestern Gondwana survived and were immediately joined by a number of immigrant taxa to occupy most of the vacant niches of the earliest Triassic. Preserved in the Karoo Basin of South Africa is an almost continuous stratigraphic record of terrestrial sedimentation through the PTB that hosts a fossil record of ecosystem collapse, survivorship and recovery. The adaptation of the mammal like reptiles (therapsids) of the Lystrosaurus Assemblage Zone to a highly seasonal, potentially drought prone semi-arid earliest Triassic Karoo Basin is associated with changes in modes of fossilisation. Isolated dicynodont skulls and postcranial elements are commonly found in the latest Permian. However, in the earliest Triassic the dicynodonts occur as articulated, curled-up skeletons and multi-individual monotaxic bonebeds. Lack of epiphyses and relatively small skull length confirm that the bonebeds comprise several subadult Lystrosaurus declivis (L. declivis) carcasses. No significant evidence for hydraulic bone concentration along with clusters of ribs in life position point to complete carcasses being present at the site of death, and suggest that animals behaviourally congregated before perishing together. The bonebeds are hosted by an 8 m thick horizon of floodplain mudrocks in the lower Katberg Formation named the Lystrosaurus abundant zone. The bonebed horizon is overlain by sand-filled mud cracks capped by coarse sediments indicative of rapid deposition during waning floods. Stable isotope analyses of pedogenic and early diagenetic calcite nodules in association with the bonebeds yield average δ13C values ranging from − 9.5 to − 5‰ and δ18O values of 13.5 to 16‰, respectively. These isotope values support a seasonally cold, semi-arid climate at high latitude (~ 55ºS). The presence of vertebrate burrow casts on bonebed horizons and evidence of shelter sharing suggests tetrapods were attempting to escape extreme climatic conditions. Aggregation behaviour of subadult Lystrosaurus during unusual cold snaps may best explain the origin of bonebed assemblages.

PT Extinction Surviving Dicynodont Lineage Was Too Morphologically Conservative to Exploit New Niches

Ancient mammal relatives cast light on recovery after mass extinction

The study's findings are surprising as much research so far suggests that the survivors of mass extinctions are often presented with new ecological opportunities because the loss of many species in their communities allows them to evolve new lifestyles and new anatomical features as they fill the roles vacated by the victims. However, it turns out that not all survivors respond in the same way, and some may not be able to exploit fully the new opportunities arising after a mass extinction.

Dr Marcello Ruta of the University of Lincoln, with colleagues from the Field Museum of Natural History in Chicago, the Museum für Naturkunde in Berlin and the University of Bristol, studied how anomodonts responded in the aftermath of the end-Permian mass extinction, about 252 million years ago, when as many as 90 per cent of marine organisms and 70 per cent of terrestrial species became extinct.

Near the end of the Permian, a large number of anomodont species existed with a wide range of body sizes and ecological adaptations, including terrestrial plant eaters, amphibious hippo-like species, specialized burrowers, and even tree-dwelling forms. The most successful group of anomodonts, with canine-like tusks in their upper jaws and turtle-like beaks, were the most important terrestrial herbivores of their time.

Dr Ruta said: "The number of anomodont species increased during the Permian, sharply dropped during the end-Permian extinction event, and then rebounded in the Middle Triassic Period (about 240 million years ago) before the final extinction of the group at the end of the Triassic.

"However, the variety of different anatomical features found in anomodonts – that is, their anatomical diversity – declined steadily over their history. Even in the aftermath of the mass extinction, when there should have been a lot of empty ecological space, anomodonts did not evolve any fundamentally new features. Rather than allowing them to move to a new evolutionary trajectory, the genetic bottleneck they passed through constrained their future evolution."

Analyzing the response of animals and plants to this catastrophe helps scientists understand models of diversification and patterns of ecosystem reconstruction following large-scale biological crises.

Obviously Benton et al do not believe the fossil recovered from Australia is a Cretaceous dicynodont.

Open access paper link.

Angonisaurus and Shansiodon: Dicynodonts From the Middle Triassic

Angonisaurus and Shansiodon, dicynodonts (Therapsida, Anomodontia) from subzone C of the Cynognathus Assemblage Zone (Middle Triassic) of South Africa

Authors:

1. P. John Hancox (a)
2. Kenneth D. Angielczyka (b)
3. Bruce S. Rubidge (a)

Affiliations:

a. Bernard Price Institute for Palaeontological Research, School for Geosciences , University of the Witwatersrand , PO Wits , 2050 , South Africa

b. Department of Geology , Field Museum of Natural History , 1400 South Lake Shore Drive, Chicago , Illinois , 60605 , U.S.A.

Abstract:

Dicynodonts are the most abundant therapsids from the Beaufort Group (Karoo Basin, South Africa), and they have been used as index fossils to define most of the Beaufort biozones. Although speciose during the Late Permian, dicynodont diversity was greatly reduced by the end-Permian mass extinction. The Cynognathus Assemblage Zone, the uppermost biozone of the Beaufort Group, is traditionally known to host only the dicynodonts Kannemeyeria simocephalus and Kombuisia frerensis. Recent biostratigraphic research in this biozone has revealed the presence of two more poorly known dicynodont genera, Angonisaurus and Shansiodon, which are biostratigraphically constrained to the uppermost Cynognathus Assemblage Zone (subzone C). Although these taxa have been reported from subzone C of the Cynognathus Assemblage Zone previously, we provide the first detailed description of the material in question and justifications for the taxonomic identifications. The presence of Angonisaurus in the Cynognathus subzone C allows a direct correlation between this assemblage and that of the Lifua Member of the Manda beds in Tanzania. A correlation with the Antarctic upper Fremouw Formation also may be possible, but is less certain. The presence of Shansiodon allows a direct correlation with the upper Ermaying Formation of China, but we reject the previously proposed global ‘Shansiodon biochron’ because Shansiodon sensu stricto only occurs in China and South Africa. Biogeographically, Angonisaurus appears to have been widespread but rare in southern Gondwana, and the unusual distribution of Shansiodon mirrors that of Diictodon feliceps in the Permian. Southern African dicynodont assemblages display increased provinciality in the Middle Triassic.

Tasmanian Triassic Dicynodont Found

A Tasmanian couple on a quiet walk down to the beach a few years ago discovered a fossil that scientists say is 250 million years old.

Bob and Penny Tyson found the fossilised remains of a dicynodont, a tusked plant-eating animal that's believed to be a distant ancestor of modern mammals.

Roughly the size of a cow, it had two tusks and a horny beak.

Queensland Museum palaeontologist Andrew Rozefelds says the dicynodont lived on every continent, including Antarctica.

The ABC reports that until now, the only specimen previously found in Australia was in Queensland almost 30 years ago.

He describes the dicynodont as a ''strange-looking beast''.

''They had tusks at the front of their skull, which makes you think maybe they were a carnivore, but in fact they were a plant eater.

''They had slightly splayed legs, so their posture was quite different to say some of the modern mammals you see and they're very, very distantly related to modern mammals.''

I don't see a paper at the JVP. However, considering the journal is a little outdated from the last time they updated what's online, I'm not surprised. Previously, in Tasmania the predominant fossils were temnospondyls. And not much else.

Tiarajudens eccentricus Skull Pic

A Sabre Toothed Anomondont: Tiarajudens eccentricus

Thriving long before the dinosaur age, Tiarajudens eccentricus was armed with an incredible arsenal of teeth for grinding, tearing, and even scaring. But the newly discovered saber-toothed mammal ancestor was a vegetarian, a new study says.

Not only did the big-dog-size animal have huge canines—each as large as a crayon—but the roof of the animal's mouth appears to have been studded with teeth, which allowed for rapid replacement of lost teeth, as in sharks, researchers say.

Part of the Anomodontia suborder within the Therapsida order—often called mammal-like reptiles—the 260-million-year-old fossil vegetarian "looks like a combination of different animals, and it takes some time to believe it when you see this animal in front of you," said paleontologist Juan Carlos Cisneros, who discovered the fossil in Brazil.

"It has the incisors of a horse, which are very good for cutting and pulling plants; the big molars of a capybara (picture), for grinding; and the canines of a saber-toothed cat."

(Related: "'Social' Sabertooths Hunted in Packs, Study Says.")

Paleontologist Jörg Fröbisch said the saber teeth are a particular surprise, considering the animal's diet of fibrous plants.

"You would usually expect saber teeth in a carnivore," said Fröbisch, of the Humboldt University of Berlin.

"The best known animals are obviously saber-toothed cats or tigers, but there are also some [extinct] forms known among the marsupials, relatives of kangaroos and wombats," added Fröbisch, who wasn't involved in the Tiarajudens eccentricus study, to be published tomorrow in the journal Science.

T. eccentricus' saber teeth might have deterred predators or intimidated or wounded rivals of the same species, the study authors speculate.

"Saber teeth used for display or fighting between members of the same species is something that we thought appeared in herbivores less than 60 million years ago," said study leader Cisneros, of Brazil's Federal University of Piauí.

"If Tiarajudens eccentricus [used them this way], then it appeared much earlier, when terrestrial communities were ... dominated by herbivores."

[...]

These unique dental adaptations may also offer some clues to the striking success of the anomodonts during the middle Permian era, before dinosaurs dominated Earth. (See a prehistoric time line.)

"Anomodonts were the most successful group of terrestrial vertebrates, with the most species, most diverse morphologies, and most ecological adaptations during this time," the University of Humboldt's Fröbisch said.

"There were burrowing forms, climbing forms, semiaquatic forms, small rat-sized animals, and large cow-sized animals in this same group, and this is unique in the ancestral lineage of mammals," he said.

ummm. They are not mammal ancestors!!! grr.

still cool though.

The Postcranial Anatomy of Suminia getmanovi (Synapsida: Anomodontia)

The postcranial anatomy of Suminia getmanovi (Synapsida: Anomodontia), the earliest known arboreal tetrapod

JÖRG FRÖBISCH, ROBERT R. REISZ

Article first published online: 21 JAN 2011

DOI: 10.1111/j.1096-3642.2010.00685.x

Abstract:

The basal anomodont Suminia getmanovi Ivakhnenko, 1994 from the late Palaeozoic of Russia is highly specialized in its masticatory apparatus, and has been suggested to represent the earliest arboreal tetrapod in the fossil record. Its postcranial anatomy is described in detail for the first time, revealing a large number of autapomorphies for this small herbivore. These include a reduced number of presacral and therein dorsal vertebrae, an elongate neck, a long and possibly prehensile tail, a procoracoid with a notch at its ventromedial margin rather than a foramen, an iliac blade with a robust ridge at its anteromedial edge, a pubis with a puboischiadic fenestra and separate pubic foramen, and elongate limbs. Additional autapomorphic characters are displayed in the autopodium, which comprises about 40% of the entire limb length. These features include an enlarged, phalangiform distal carpal 1 and tarsal 1, a short and robust first metacarpal, a crescent-shaped distal tarsal 4, and elongate penultimate phalangeal elements. The phylogenetic relationships of basal anomodonts are revisited using an expanded data set, with the addition of key taxa and several postcranial characters. Unlike dicynodonts, Suminia retained the plesiomorphic phalangeal formula for amniotes of 2-3-4-5-3 (manus) and 2-3-4-5-4 (pes). This pattern is achieved by the retention of disc-like phalangeal elements between the proximal and penultimate phalanges in digits III, IV (manus and pes), and V (pes only). In light of the new material, Suminia can be recognized as the most complete basal anomodont, offering new insights into the early evolution of the group.

Awesome. More related to this...sometime. lol.

Uranocentrodon & Lystrosaurus: Wow!

That is seriously kewl. Go look at Dmitry Bogdanov's gallery for more.

Dicynodont Diversity Through the Permian/PT Extinction/Triassic

Global Taxonomic Diversity of Anomodonts (Tetrapoda, Therapsida) and the Terrestrial Rock Record Across the Permian-Triassic Boundary

Jörg Fröbisch (1,*)

1. Department of Biology, University of Toronto, Mississauga, Ontario, Canada

* E-mail: jorg.frobisch@utoronto.ca
Abstract:

The end-Permian biotic crisis (~252.5 Ma) represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids (‘mammal-like reptiles’), through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals that anomodonts experienced three distinct phases of diversification interrupted by the same number of extinctions, i.e. an end-Guadalupian, an end-Permian, and a mid-Triassic extinction. A positive correlation between the number of taxa and the number of formations per time interval shows that anomodont diversity is biased by the Permian-Triassic terrestrial rock record. Normalized diversity curves indicate that anomodont richness continuously declines from the Middle Permian to the Late Triassic, but also reveals all three extinction events. Taxonomic rates (origination and extinction) indicate that the end-Guadalupian and end-Permian extinctions were driven by increased rates of extinction as well as low origination rates. However, this pattern is not evident at the final decline of anomodont diversity during the Middle Triassic. Therefore, it remains unclear whether the Middle Triassic extinction represents a gradual or abrupt event that is unique to anomodonts or more common among terrestrial tetrapods. The end-Permian extinction represents the most distinct event in terms of decline in anomodont richness and turnover rates.

Missed this one somehow. Interesting stuff.