The First Report of a Forest From Mid to Late Permian China

First report of a phytogeographically mixed (transitional) Middle–Late Permian fossil wood assemblage from the Hami area, northwest China, and implications for Permian phytogeographical, paleogeographical and paleoclimatic evolution in central Asia

Authors:

Wei et al

Abstract:

A diverse and well-preserved fossil wood assemblage is described, for the first time, from the Middle Permian Taerlang Formation and the Upper Permian Quanzijie Formation in the vicinity of the Tianshan Town, Hami City of northwestern China. On the basis of wood microstructure, the fossil woods are classified into three genera and five species, including one new genus: Prototianshanoxylon gen. nov. and two new species: Prototianshanoxylon erdaogouense sp. nov., Prototianshanoxylon hamiense sp. nov. The new genus is characterized by window-like cross-field pitting and mixed tracheid radial wall pitting that suggest a transitional type between araucarioid-type and protopinoid-type pittings.

Phytogeographically, the fossil wood assemblage is characterized by an admixture of elements of both temperate Angaran (represented by wood specimens with moderately to well defined growth rings in their secondary xylem) and tropical–subtropical north subregion of the Cathaysian floras (with wood specimens lacking well-defined growth rings). Such a phytogeographically mixed fossil wood assemblage is interpreted to represent a transitional and complex climate condition between a cool temperate and tropical to subtropical zones, showing both seasonal variation and unstable climate conditions. Previously, similarly mixed floras have already been found to exist widely in northern China ranging in age from Early to Late Permian, but the mechanisms thought to be responsible for their formation were varied and remain controversial. In this study, the formation of these mixed Permian floras of North China is linked to the closure of the Tianshan–Hingan seaway coupled with the collision and amalgamation of Siberia with North China and the Tarim block, in a manner much like closing a pair of scissors with the closure of the seaway proceeding gradually and progressively from west to the east.

Evidence of Insect Herbivory From Middle Permian Antarctica

Animal–plant interactions in a Middle Permian permineralised peat of the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica

Authors:

Slater et al

Abstract:

Evidence for invertebrate feeding on glossopterid gymnosperms is documented from Middle Permian silicified peats of the Prince Charles Mountains, Antarctica, in the form of coprolites occurring both free in the peat matrix and clustered within excavations in roots, aerial wood and leaves. Observations of coprolites in thin-sections of the peats and from scanning electron microscopy of examples extracted via bulk maceration reveal nine morphotypes distinguished by size, shape, surface texture and contents. These include coprolites with coarse plant debris, spirally ornamented coprolites, coprolites containing spore/pollen remains and fern sporangia, coprolites within Glossopteris leaves, an ellipsoidal morphotype within a fern sporangium, large isolated coprolites between matted leaves, clustered forms filling galleries inside Vertebraria roots and Australoxylon wood, forms with coarse indeterminate constituents and others with fungal contents. Other faunal evidence is limited to indeterminate arthropod exoskeleton fragments. Collectively, the coprolites within the permineralised peat from the Prince Charles Mountains document the presence of diverse feeding behaviours including stem feeding, sporangial feeding, palynivory, root feeding and mycophagy. The first evidence of invertebrate feeding traces in Vertebraria (glossopterid) roots is identified. These findings indicate that herbivory by invertebrates in the high-latitude Permian forest-mire ecosystems of Antarctica was more intense and diverse than previous studies have reported, and affected all parts of the Glossopteris plant, together with components of associated herbaceous taxa.

Crustaceans Just Before the Permian Extinction

Evolution of Crustaceans at the edge of the end-Permian crisis: Ichnonetwork analysis of the fluvial succession of Nurra (Permian–Triassic, Sardinia, Italy)

Authors:

Baucon et al

Abstract:

Decapod crustaceans are among the most efficient ecosystem engineers of the Phanerozoic, but the path that led to their engineering success is poorly known. The Permian–Triassic continental succession of Nurra (early Cisuralian–early Middle Triassic; Sardinia, Italy) sheds light on this obscure subject, because it preserves the oldest (Roadian) fluvial Ophiomorpha and Camborygma, ascribed to ghost shrimps (Decapoda: Axiidea, Gebiidea) and crayfishes (Decapoda: Astacidea, Parastacidea), respectively. These crustacean trace fossils are part of a well-preserved ichnofauna including Arenicolites, Diplocraterion, Helminthoidichnites, Palaeophycus, Planolites, rhizoliths, Skolithos, Spongeliomorpha, Taenidium, Treptichnus, alongside an undetermined tetrapod footprint, helical burrows and Sinusichnus-like traces.

In light of the abundance of crustacean trace fossils, the Cala Viola section (Roadian–Anisian) was selected for ichnonetwork analysis. This novel approach, focusing on the topology of the association relationships of ichnotaxa, revealed six ichnoassociations, i.e., Rhizohaloes, Taenidium/Ophiomorpha, Helminthoidichnites, Palaeophycus, Skolithos and Arenicolites ichnoassociations. In addition, ichnonetwork analysis shown that Camborygma and Ophiomorpha colonised adjacent, partially overlapping fluvial subenvironments, ranging from active fluvial channels to periaquatic overbanks. As the Nurra occurrences are penecontemporaneous of the astacid/thalassinid diversification (Carboniferous–Early Permian) and coeval with the appearance of crayfishes (Middle Permian), fluvial environments played an important role in the evolution of both crayfishes and ghost shrimps. The most parsimonious explanation of the observed scenario is that astacid–thalassinid diversification happened in fluvial environments between the Carboniferous and Early Permian, while ghost shrimps invaded marine environments at the Permian–Triassic boundary. In addition, ichnonetwork analysis revealed that the ichnological system simplified across the Permian–Triassic boundary, accounting for a structured Permian ecosystem and fragmented, stressed habitats during the Early Triassic. This scenario is explained by a progressive drying trend that dramatically changed the hydrological features across the Permian–Triassic boundary. This supports the crucial role of global warming in driving the end-Permian crisis and its prolonged recovery.

The Late Permian Tropics May Have Been a Wasteland

Extremely high temperatures and paleoclimate trends recorded in Permian ephemeral lake halite

Authors:

1. James J. Zambito IV (a)

2. Kathleen C. Benison (a)

Affiliations:

a. West Virginia University, Department of Geology and Geography, P.O. Box 6300, Morgantown, West Virginia 26506-6300, USA

Abstract:

Although the late Paleozoic deglaciation is arguably one of the best deep-time analogs for current and predicted climate change, quantitative paleotemperature data from this interval are generally lacking. We reconstruct extreme paleoweather conditions and paleoclimate changes from Permian Nippewalla Group (probably uppermost Leonardian/Kungurian; North America) ephemeral lake halite by using fluid inclusion homogenization temperatures to directly measure the water temperature when the halite precipitated; in these depositional settings, this is an excellent air temperature proxy. Extremely high temperatures, to 73 °C, and large diurnal temperature ranges are evidenced in the lower Nippewalla Group, suggesting conditions more extreme than anywhere on Earth today. In contrast, the upper Nippewalla Group was cooler; maximum temperature was 43 °C and diurnal temperature ranges were smaller, though even these conditions are similar to modern extremely hot environments. Comparison to prior studies suggests that these results may be indicative of regional patterns. This study represents the first pre-Quaternary high-resolution quantitative data set of extreme paleoweather and possible paleoclimate trends from fluid inclusions in halite, and provides new insight into climate change during the late Paleozoic deglaciation.

Bunostegos: a Desert Dwelling Relic Pareiasaur From the Late Permian Niger

During the Permian era, the Earth was dominated by a single supercontinent called Pangea – "All-Earth". Animal and plant life dispersed broadly across this land, as documented by identical fossil species found on multiple modern continents. But a new study published in the Journal of Vertebrate Paleontology supports the idea that there was an isolated desert in the middle of Pangea with a fauna all its own.

Roaming this desert in what is now northern Niger was a very distinctive creature known as a pareiasaur. Pareiasaurs were large, herbivorous reptiles that were common across Pangea during the Middle and Late Permian, about 266-252 million years ago. "Imagine a cow-sized, plant-eating reptile with a knobby skull and bony armor down its back," said lead author Linda Tsuji. The newly discovered fossils belong to the aptly-named genus Bunostegos, which means "knobby [skull] roof."

Most pareiasaurs had bony knobs on their skulls, but Bunostegos sported the largest, most bulbous ones ever discovered. In life, these were probably skin-covered horns like those on the heads of modern giraffes. Although at first blush these features seem to suggest that Bunostegos was an evolutionarily advanced pareiasaur, it also had many primitive characteristics. Tsuji's analysis showed that Bunostegos was actually more closely related to older and more primitive pareiasaurs, leading to two conclusions: first, that its knobby noggin was the result of convergent evolution, and second, that its genealogical lineage had been isolated for millions of years.

So how do you isolate a population of cow-sized reptiles? Though there were no fences in the Permian, climatic conditions conspired to corral Bunostegos – along with several other reptiles, amphibians, and plants – and keep them constrained to the central area of the supercontinent. "Our work supports the theory that central Pangea was climatically isolated, allowing a unique relict fauna to persist into the Late Permian," said Christian Sidor, another author of the paper. This is surprising because areas outside this central region show fossil evidence of regular faunal interchange.

Geological data also show that central Pangea was hyperarid (extremely dry), effectively discouraging some animals from passing through, while keeping those within from venturing out. The long period of isolation under these parched conditions gave Bunostegos lineage time to evolve its unique anatomical features.

Paleontologist Gabe Bever, who was not involved with the study, said "Research in these lesser-known basins is critically important for meaningful interpretation of the Permian fossil record. Our understanding of the Permian and the mass extinction that ended it depends on discovery of more fossils like the beautifully bizarre Bunostegos."

Paper link later.

Permian Parasite Fossil

A cluster of tapeworm eggs discovered in 270-million-year-old fossilized shark feces suggests that intestinal parasites in vertebrates are much older than previously known, according to research published January 30 in the open access journal PLOS ONE by Paula Dentzien-Dias and colleagues from the Federal University of Rio Grande, Brazil.

Remains of such parasites in vertebrates from this era are rare- of 500 samples examined, only one revealed the tapeworm eggs. This particular discovery helps establish a timeline for the evolution of present-day parasitic tapeworms that occur in foods like pork, fish and beef. The fossilized eggs were found in a cluster very similar to those laid by modern tapeworms. Some of them are un-hatched and one contains what appears to be a developing larva. According to the study, "This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was previously known and occurred at least 270-300 million years ago."

Something Big Was Eating Tetrapods and Fish in the Wujiapingian Permian of Russian

Upper Permian vertebrate coprolites from Vyazniki and Gorokhovets, Vyatkian Regional Stage, Russian Platform

Authors:

1. Krzysztof Owock (a)
2. Grzegorz Niedźwiedzki (b, c, *)
3. Andrey G. Sennikov (d)
4. Valeriy K. Golubev (d)
5. Katarzyna Janiszewska (a)
6. Tomasz Sulej (a)

Affiliations:

a. Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818, Warsaw, Poland

b. Department of Organismal Biology, Uppsala University, Norbyvägen 18A, 752 36
Uppsala, Sweden

c. Department of Paleobiology and Evolution, Faculty of Biology, University of Warsaw, Stefana Banacha 2, 02-097 Warsaw, Poland

d. Borissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya 123, Moscow, 117997 Russia,

*. Corresponding author. Email: grzegorz.niedzwiedzki@ebc.uu.se

Abstract:

Numerous coprolites have been found in the Vyazniki and Gorokhovets localities of European Russia. Five identified coprolite-bearing horizons occur in the upper Permian deposits of the Vyatkian Regional Stage. Coprolites were collected from mudstone with a coprolite breccia-like layer and also from intraformational conglomerates that were deposited in a floodplain and overbank environment. Two coprolite morphotypes (A and B) are recognized from size and shape analysis of 32 specimens. Morphotype A has long, nonsegmented feces. Smaller, cylindrical or tubular-shaped coprolites of morphotype B are commonly segmented. SEM images of the coprolite matrix show spheres and thinwalled vesicles with diameters 0.5–4 μm. Electron Micro Probe (EMP) analyses of polished thin sections show microcrystalline carbonate-fluoride-bearing calcium phosphate with small amounts of calcium replaced in the crystal lattice. Optical microscopy and EMP investigations show that iron and manganese oxides are responsible for elevated iron and manganese concentrations in the bulk mass of coprolites. Other metals (V, Ni) can be associated with oxides forming spheroids with diameters 3–10 μm. REEs (rare earth elements, U, and other trace element concentrations suggest significant eolian sediment input to the burial environment of the coprolites. The scats contain fish scales and bones of tetrapods (amphibians or reptiles). In one large-sized coprolite, a small fragment of therapsid bone was also found. Both morphotypes are matched to carnivorous taxa within the Archosaurus rossicus zone of the Eastern Europe. The size and shape of the best-preserved specimens suggest that they were possibly produced by a large therapsid, anthracosaur, or early archosauromorph predator.

Global Warming's Contributions to the Permian Extinction

Impacts of global warming on Permo-Triassic terrestrial ecosystems

Authors:

1. Michael J. Benton (a)
2. Andrew J. Newell (b)

Affiliations:

a. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK
b. British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK

Abstract:

Geologists and palaeontologists have expressed mixed views about the effects of the end-Permian mass extinction on continental habitats and on terrestrial life. Current work suggests that the effects on land were substantial, with massive erosion following the stripping of vegetation, associated with long-term aridification and short-term bursts of warming and acid rain. Wildfires at the Permo-Triassic boundary contributed to the removal of forests and the prolonged absence of forests from the Earth's surface for up to 10 Myr. These physical crises on land impinged on the oceans, suggesting tight interlocking of terrestrial and marine crises. Levels of extinction on land may well have been as high as in the sea, and this is certainly the case for tetrapods. The mass extinction seems to have been less profound for plants and insects, but it is hard at present to disentangle issues of data quality from reductions in abundance and diversity. Several killing agents have been proposed, and of these tetrapods may have succumbed primarily to acid rain, mass wasting, and aridification. Plants may have been more affected by the sudden effects of heating and wildfires, and the crisis for insects has yet to be explored.

Can I get a copy of the PDF? For some reason I cannot get it.

A Snapshot of the Early Permian Chemnitz Petrified Forest

A Snapshot of an Early Permian Ecosystem Preserved by Explosive Volcanism: New Results From the Chemnitz Petrified Forest, Germany

Authors:

1. RONNY RÖßLER (a)
2. THORID ZIEROLD (a)
3. ZHUO FENG (a,b)
4. RALPH KRETZSCHMAR (a)
5. MATHIAS MERBITZ (a)
6. VOLKER ANNACKER (a)
8. JÖRG W. SCHNEIDER (c)

Affiliations:

a. DAStietz, Museum für Naturkunde, Moritzstraße 20, D-09111 Chemnitz, Germany,

b. Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming 650091, People's Republic of China

c. Geological Institute, Technische Universität Bergakademie Freiberg, Bernhard-von-Cotta-Strasse 2, 09596 Freiberg, Germany

Abstract:

A recently excavated locality in the Chemnitz Petrified Forest, lower Permian in age and occurring within the Leukersdorf Formation of the Chemnitz Basin, Germany, provides evidence for an outstanding fossil assemblage buried in situ by pyroclastics. The environment is interpreted as forested lowland that sheltered a dense hygrophilous vegetation of ferns, sphenophytes, and gymnosperms, as well as a diverse fauna of reptiles, amphibians, arthropods, and gastropods. A detailed measured section of the outcrop documents the early volcanic history of the Chemnitz fossil forest, including a paleosol that shows the root systems of Psaronius tree ferns, Arthropitys calamitaleans, and Medullosa and Cordaixylon gymnosperms in the same horizon. Fifty-three trunks are still standing upright and rooted at their place of growth, providing evidence that the top of the paleosol was the land surface on which the forest grew, thereby offering insights into the original plant community structure and density. Taphonomic analysis of both the petrified and adpression-fossil assemblages enable us to reconstruct the direction, estimate the violence and extent of the volcanic events, and their effects on the entire ecosystem. A complete dataset of three-dimensional coordinates resulting from three and one-half years of continuing excavation and study permits the recognition of organ connections and results in the first reconstructions of the excavation site, the floral elements, and the plant community as a whole.

Diversity of Tetrapod Herbivores From the Late Carboniferous to the Mid Triassic

Reconstructing the diversity of early terrestrial herbivorous tetrapods

Authors:

1. Marianne R. Pearson (a.*)
2. Roger B.J. Benson (a, b)
3. Paul Upchurch (a)
6. Jörg Fröbisch (c)
5. Christian F. Kammerer (c)

Affiliations:

a. University College London, Department of Earth Sciences

b. University of Cambridge, Department of Earth Sciences

c. Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung an der Humboldt-Universität zu Berlin

*.  Author With Whom Communication Is Intended: Email:marianne.pearson@ucl.ac.uk

Abstract:

Terrestrial herbivorous tetrapods first appear in the fossil record during the Late Carboniferous (306.5 Ma). The diversification of herbivores is a key aspect of the transition to the modern trophic structure of terrestrial vertebrate ecosystems, because it allowed tetrapods to exploit terrestrial (i.e. non-aquatic) primary productivity. However, the palaeodiversity dynamics of the earliest terrestrial vertebrate herbivores have received relatively little attention, apart from a few studies that focus on specific clades. A new data set containing 287 species occurrences of herbivorous tetrapods including the major Palaeozoic and Early Triassic clades Anomodontia, Archosauromorpha, Bolosauridae, Captorhinidae, Caseidae, Cynodontia, Dinocephalia, Diadectomorpha, Edaphosauridae, Pareiasauria, Poposauroidea, Procolophonoidea, Rhynchosauria, Silesauridae and Therocephalia is used to analyse palaeodiversity from the Late Carboniferous to the Middle Triassic (~ 306.5 – ~ 236 Ma), taking into account the effects of potential sampling biases by using the number of tetrapod-bearing formations as a proxy. The results support a gradual increase in taxic diversity from the Late Carboniferous to the Wordian, followed by a dip in diversity during the Guadalupian (Middle Permian), and an increase to a peak in the Late Permian at the Wuchiapingian/Changhsingian boundary. Herbivorous tetrapods were strongly affected by the end-Permian mass extinction with both the herbivorous Pareiasauria and Captorhinidae becoming extinct and the observed number of anomodont species decreasing by up to 80%. The drop in observed diversity at the end Permian is dampened slightly because of the radiation of new herbivorous forms during the Early Triassic. A strong biological signal is apparent even after correcting for sampling.

They use the "Land Vertebrate Faunachrons", which I thought were considered flawed.

Sooo...not sure what the accuracy of this is. I Am Not a Triassic (or any really) Paleontologist though.

Permian Fall in Our Own Backyards

Gingko on the left.  Redwood on the right.  Too bad my phone just sucks for pix.

Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa

Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa

Authors:

1. Nicholas Fordyce (a)
2. Roger Smith (b)
3. Anusuya Chinsamy (a)

Affiliations:

a. Department of Zoology, University of Cape Town, Cape Town, South Africa
b. Iziko South African Museum, Cape Town, South Africa

Abstract:

Dicynodonts are an extinct group of herbivorous non-mammalian therapsids (‘mammal-like’ reptiles) that are widely known from terrestrial Permo-Triassic strata throughout Pangaea. Dicynodont fossil remains are common within the Late Permian Beaufort Group of the Karoo Basin in South Africa. A large, partially articulated dicynodont skeleton recovered from the Tropidostoma Assemblage Zone is taphonomically important in having an unusual disarticulation pattern, bone surface punctures and a broken tooth of an unidentified carnivore associated with it. Here we report on the nature of the bone damage, and the identity of the carnivore that lost a canine tooth whilst scavenging the dicynodont carcass. The morphological characteristics of the serrations on the unidentified tooth were compared with those of contemporaneous carnivores, the gorgonopsians and therocephalians. Scanning electron microscopy analysis of a silicone cast of the unidentified tooth revealed distinctive 0.5-mm square-shaped serrations. Our comparative assessment of the tooth size, curvature, cross-sectional shape and morphology of the serrations revealed that the unidentified canine most closely matched Aelurognathus, a gorgonopsian known from the same assemblage zone.

Gorgons going hyena here.  Kewl!

The paper is open access, btw.

Varanopids Coexisted with More Advanced Synapsids

(Heleosaurus, a varanopid)

A species of ancient predator with saw-like teeth, sleek bodies and a voracious appetite for meat survived a major extinction at a time when the distant relatives of mammals ruled the earth.

A detailed description of a fossil that scientists identify as a varanopid "pelycosaur" is published in the December issue of Naturwissenschaften – The Science of Nature. Professors Sean Modesto from Cape Breton University, and Robert Reisz from University of Toronto Mississauga provide evidence that a group of ancient, agile predators called varanopids survived for more than 35 million years, and co-existed with more advanced animals.

Modesto and the team performed a detailed examination of the partial skull and jaw of the youngest known primitive mammal-like animal, which they believe lived over 260 million years ago in the Permian Period. The fossils are from rocks forming the Pristerognathus Assemblage Zone of the Beaufort Group in South Africa.

"These animals were the most agile predators of their time, sleek-looking when compared to their contemporaries," says Reisz. "They seem to have survived a major change in the terrestrial fauna that occurred during the Middle Permian, a poorly understood extinction event in the history of life on land."

According to Modesto, who was once a student at U of T Mississauga, "these ancient animals really looked like modern goannas or monitor lizards, but are actually more closely related to mammals."

The fossil revealed teeth that are strongly flattened, curved towards the throat and with finely serrated cutting edges typical of hypercarnivores--animals with a diet that consists of more than 70 per cent meat.

Modesto and his colleagues concluded that these varanopids had a longer co-existence with animals that eventually evolved into mammals than previously believed. They suggest that the dental and skeletal design of varanopids, reminiscent of the Komodo dragon of today, may have contributed to their long survival and their success.

no time. But VERY interesting.

Return to the XenoPermian: Geological Staging Differences

Geological Timing Differences:

There are some serious differences between the timeline of the XenoPermian and our own. In the stages of geology alone happens to be one such. We're going to highlight a few here with the help of the above graphic. You will note that it is similar to the USGS graphic of the geological periods. However, the differences are glaring too.

Starting from the deepest geological time period, the divergences began with the Permian Period. The PT Extinction never happened in this tour de force. Rather than ending the Permian at 251 MYA, witht he eruptions of the Siberian Traps, the traps erupted over a much longer period that lasted from the Guadelupean Extinction to 245 MYA. Their effect was tolerated a lot more by the biosphere and the Permian - now XenoPermian - extends all the way up with its evolving Paleozoic ecosystems until 199.6 MYA. This is marked by the XenoPermian-Jurassic Extinctions. This marked the end of the Paleozoic and the start of the Mesozoic.

Obviously, the Mesozoic has been curtailed since the Triassic has simply ceased to exist under the Xenopermian TL. However, through a fluke of orbital mechanics, the Cretaceous and by extension the Mesozoic was extended to 55.8 MYA. The rock that ended the Mesozoic instead of landing in Chicxulub, Mexico on the Yucatan Peninsula, the great splat hit what would have been Bristol, England and caused a slightly milder mass extinction. The Cretaceous is now divided up into the Upper, Middle and Lower Epochs.

The Allozoic picks up where the Mesozoic left off and there is a distinct difference between the Allozoic and the Cenozoic. The Paleocene is history and the Paleogene and Tertiary is also circumscribed.

Next up, Paleoenvironmental differences between our Permian & Triassic and the XenoPermian. This will actually be in the next week.

For previous XenoPermian posts look here.

Glossopteris

Accute Hearing in Parareptiles and an Interesting Buried Comment

Impedance-Matching Hearing in Paleozoic Reptiles: Evidence of Advanced Sensory Perception at an Early Stage of Amniote Evolution

1. Johannes Müller*,

2. Linda A. Tsuji

Humboldt-Universität zu Berlin, Museum für Naturkunde, Berlin, Germany


Abstract:

Background

Insights into the onset of evolutionary novelties are key to the understanding of amniote origins and diversification. The possession of an impedance-matching tympanic middle ear is characteristic of all terrestrial vertebrates with a sophisticated hearing sense and an adaptively important feature of many modern terrestrial vertebrates. Whereas tympanic ears seem to have evolved multiple times within tetrapods, especially among crown-group members such as frogs, mammals, squamates, turtles, crocodiles, and birds, the presence of true tympanic ears has never been recorded in a Paleozoic amniote, suggesting they evolved fairly recently in amniote history.

Methodology/Principal Findings

In the present study, we performed a morphological examination and a phylogenetic analysis of poorly known parareptiles from the Middle Permian of the Mezen River Basin in Russia. We recovered a well-supported clade that is characterized by a unique cheek morphology indicative of a tympanum stretching across large parts of the temporal region to an extent not seen in other amniotes, fossil or extant, and a braincase specialized in showing modifications clearly related to an increase in auditory function, unlike the braincase of any other Paleozoic tetrapod. In addition, we estimated the ratio of the tympanum area relative to the stapedial footplate for the basalmost taxon of the clade, which, at 23:1, is in close correspondence to that of modern amniotes capable of efficient impedance-matching hearing.


Conclusions/Significance

Using modern amniotes as analogues, the possession of an impedance-matching middle ear in these parareptiles suggests unique ecological adaptations potentially related to living in dim-light environments. More importantly, our results demonstrate that already at an early stage of amniote diversification, and prior to the Permo-Triassic extinction event, the complexity of terrestrial vertebrate ecosystems had reached a level that proved advanced sensory perception to be of notable adaptive significance.

Paper link above. Think gecko or aye-aye parareptile here.

The interesting comment?

If so, then adaptations to dim-light environments might have been the driving force not only in the diversification of the herein investigated taxa, but even more so in the procolophonoids, and were possibly an important factor in their survival of the Permo-Triassic extinction event. This interpretation can also be applied to Archosauriformes, another amniote clade that was not significantly affected by the Permio-Triassic extinction, and for which there is molecular data indicating that the clade Archosauria, which is nested within Archosauriformes, was ancestrally nocturnal [33]. In addition, the fact that Early Triassic synapsids living immediately after the extinction apparently had specific burrowing life habits [34] also suggests that adaptations to dim-light environments were potentially an important factor in the survival of the Permo-Triassic transition.

Cuz the UV blasted the diurnal species? Perhaps the PT was more selective after all?

Paleoasian Sea (???) Disappearance Nailed Down...Sorta.

Note. This is a translated article:

The collision between the Siberian Plate and North China Plate was a significant geological event in earth history, which led to the final closure of the Paleoasian Ocean and the formation of the Eurasian continent. Despite numerous research efforts in recent decades, the precise time of this event has remained a puzzle until now. New evidence in helping settle this issue is provided by Prof. Deng Shenghui and his colleagues in their paper newly published in Science in China (2009, vol.52).

Geological studies have demonstrated that during the early Paleozoic, an interval from 450-300 million year ago, the Siberian paleo-land was thousands kilometers away from the North China paleo-land, which is very different from their present situation. An immense ocean of thousands kilometers wide, namely the Paleoasian Ocean, separated these two paleo-lands. During the Carboniferous and Early Permian (about 360-270 million year ago), the North China paleo-land was located near the equator, where subtropic-tropic type of flora grew, named as "the Cathaysia Flora". In contrast, the Siberian paleo-land was located at high latitude, where temperate flora was distributed, known as "the Angara Flora". These two types of floras are very distinctive and do not mix with each other because of the geological barrier and their separate niches in different climatic zone.

Prof. Deng and his collaborators concluded that the time of the Paleoasian Ocean's disappearance is the end of the Permian, about 251 million years ago, based on their study of land plant fossils. Several years ago, Deng and his research group found many plant fossils from the rocks that were formed in the Late Permian during their stratigraphical and paleontological investigation in Heilongjiang, Northeast China. These fossils could be divided into two types after detailed identifications. One belongs to Angara Flora and the other to Cathaysia Flora. So, these plant fossils represent a mixed flora. The mixed flora implies that the Angara type plants lived together with some Cathaysia type plants at this location in the Late Permian. This means that the Paleoasian Ocean, once a barrier of plant immigration, must have disappeared in the Late Permian, and those plants grew previously in North China paleo-land now immigrated to the Siberian paleo-land. Therefore, Deng and his colleagues suggested that the Paleoasian Ocean finally closed at the end of the Late Permian, about 251 million years ago.

Paleoasian sea is probably the paleotethys. I think. Or part of it.

Oldest Known Aboreal Herbivore Found...IN THE PERMIAN!

(Reconstruction of the basal anomodont Suminia getmanovi. (a) Flesh and (b) skeletal reconstruction.)

The Late Permian herbivore Suminia and the early evolution of arboreality in terrestrial vertebrate ecosystems


Jorg Frobisch(1)*
Robert R. Reisz(2)

1 Department of Geology, The Field Museum, Chicago, IL 60605, USA
2 Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada

Vertebrates have repeatedly filled and partitioned the terrestrial ecosystem, and have been able to occupy new, previously unexplored habitats throughout their history on land. The arboreal ecospace is particularly important in vertebrate evolution because it provides new food resources and protection from large ground-dwelling predators. We investigated the skeletal anatomy of the Late Permian (approx. 260 Ma) herbivorous synapsid Suminia getmanovi and performed a morphometric analysis of the phalangeal proportions of a great variety of extant and extinct terrestrial and arboreal tetrapods to discern locomotor function and habitat preference in fossil taxa, with special reference to Suminia. The postcranial anatomy of Suminia provides the earliest skeletal evidence for prehensile abilities and arboreality in vertebrates, as indicated by its elongate limbs, intrinsic phalangeal proportions, a divergent first digit and potentially prehensile tail. The morphometric analysis further suggests a differentiation between grasping and clinging morphotypes among arboreal vertebrates, the former displaying elongated proximal phalanges and the latter showing an elongation of the penultimate phalanges. The fossil assemblage that includes Suminia demonstrates that arboreality and resource partitioning occurred shortly after the initial establishment of the modern type of terrestrial vertebrate ecosystems, with a large number of primary consumers and few top predators.


Keywords: Synapsida; Anomodontia; arboreality; terrestrial ecosystem; evolution

WOW!

A fscking Permian squirrel! Or monkey! Well, not exactly, but, fscking wow with a blink tag!

Paper link above...and it's freely available. GO READ!

UPDATE: Possible prehensile tail AND *THUMBS*.

Welcome to the XenoPermian!

The XenoPermian

This is the world that could have been, but wasn’t. This is the world that would have aborted us and all that we know. This is the world that wouldn’t have ever produced a single DaVinci or Tsailun, Machiavelli or Buddha, Armstrong or Napoleon, you or me. There wouldn’t even have been the dinosaurs as we know them or even fuzzy lolcats.

This is the world where life nearly died out over the course of tens of thousands of years because Mother Nature had a bad day 251 million years ago. This is a world that would seem terribly familiar, yet so twistedly wrong at the same time. This is not the age of mammals 186 million years early. This is something…different.

While not as ambitious as Spec-World, this is a project that three of us have embarked on. Zach of When Pigs Fly Returns, Scott of Coherent Light House, and I have been bandying around ideas for some time. We are not the only contributors to this endeavor. This was predated by a discussion that I participated in on the once mighty SHWI. Others put forward their own ideas then. However, there’s a significant difference between now and then: Zach and Scott can actually, y’know, draw. At this point, we’re ready to make the leap from bandying around to trotting out bits for display.

Over the next several months, we are hoping to parade a few different biomes, their inhabitants and their blatant strangeness across for your enjoyment, discussion, and, hopefully, critique.


The World That Would Never Be

Even though I wrote about it before, I had best do a run down as to what is happening and why. This is an alternate world, not ours. The world didn’t have the Permian Extinction as we know it happen. The Siberian Traps triggered the perfect storm that nearly undid multicellular life’s then 300 million year adventure and that never happened in this alternate world.

Rather, this time the fury of the Siberian Traps and its subsequent mass death is dissipated. The eruptions that took place over the course of a million years (+/-) are now spread over twenty million years, venting the energy and carbon dioxide over a manageable time frame for the ecology. Ten million years ought to be more than sufficient a period It is not to say that there won’t be a global warming. The world does warm. It does so over the course of ten million years and never comes close to the insane peak of the Great Dying of our timeline. The temperature of our alternate, extended Permian is a lot warmer than today: 7 C higher. Furthermore, the atmospheric oxygen does not drop to the lethal levels hat we saw during the PT Event either, nor quite to the hypothesized levels of the Mesozoic. The atmospheric oxygen “only” falls to 19%. There’s not a lot more world wide generalizations that can be made. However, in these posts we will outline and describe multiple locales.

The alternate Permian then stretches for a very long time from the end of the Carboniferous 300 million years ago to what would have been the start of the Jurassic 200 million years ago. At the end, there is a mass extinction, but it’s on the order of what happened in our Late Triassic Mass Exinctions. It isn’t pretty – the megafauna takes a hit, but “only” 50% of genera die off in the sea and 30% on land - but the horrific dying isn’t the 70% terrestrial and 90+% marine that was seen for the PT Event of our time line. That doesn’t enough the Paleozoic though. It chugs along until the Chixculub impact takes place another 135 million years in the future. Then we begin the Allozoic.

At least for now, we are going to concentrate on the extended Permian and a couple snapshots of what would have been the Triassic Period. We’ll keep the stratigraphy for now, but we may revise it later, if we make this into a full blown website or book. There are three locales that we are going to discuss. The first is the Ural Sea –official name always welcome, btw - that divides the rising Urals in the East from the rest of Pangaea in the west. We have some exciting animals and ecological discussions there: the focus though is on the littoral and beach ecologies. The star is the so-called Walrodont, but there are several other critters as well that will be detailed. The second locale is the Megavongo. This is in the heart of what would be North America and an environment that is both similar to and radically different from the Okivongo of Africa. There are no stars there, but there is an ensemble cast. The final locale is the tropical archipelago in the far eastern Tethys: the tropical islands that one day would be southern China. If we have time, we'll also hit other places, but that remains to be seen.

We are going to be starting with the Ural Sea. It's an environment somewhere between the north african Mediterranean coast and the red sea. However, with "trees" and wetter. We'll cover the environment more in the Ural Sea post itself. Had there been sentients at the time, the sphenopsids of the Ural Sea would have held the same iconic status as the cypresses of Lebanon.

Zach's first stab at using Photoshop had mixed results, but did highlight some of the critters of the XenoPermian at the Ural Sea's beach ecosystem. Pictured above are a very derived gorgonopsid chasing a family of sirenodonts, a hovasaur that is slowly becoming something not unlike a mosasaur, and our walrodonts (the very derived dicynodonts). Not pictured is our Neuparkeria (a beach comber), the procynosuchid pinnipeds, a pseudocrocodilian, some funky lobefin fish that do a grunion run, a desmodont (another very derived dicynodont), some basal pterosaurs, and a marine and uber derived Aïstopod.

They will be covered in the next post XenoPermian post.

PS Zach and I will need to collaborate in the phylogenic post of the aquatic dicynodonts, btw. They're not the only dicynodonts, but in the Ural Sea and its fringing ecology they are the single most important part of that group. And very, very interesting.

Vyazniki Biotic Assemblage of the Terminal Permian

A. G. Sennikov1 Contact Information and V. K. Golubev1 Contact Information
(1) Paleontological Institute, Russian Academy of Sciences,
Profsoyuznaya ul. 123, Moscow, 117997, Russia

Received: 30 January 2006

Abstract A new unique and diverse biotic assemblage of the terminal Permian has recently been discovered in the town of Vyazniki (Central Russia). The Vyazniki terrestrial community is transitional between Permian and Triassic ones and represents the last, so far unknown stage of the global ecological crisis of the continental biota at the Permian-Triassic boundary. The successive development of land biotic crisis in the Late Permian, which was followed by mass extinction at the Permian-Triassic boundary, and long, successive postcrisis development and specialization of new Triassic groups as well as rearrangement and diversification of the biotic assemblage composition and community structure suggest predominance of intrinsic, biotic causes of this crisis, realized in destabilization, alteration, and new stabilization of continental communities and ecosystems.

The authors interpret that the Vyazniki Biotic Assemblage as an example of the transition from Permian to Triassic faunas or in the very least a post gorgonopsid-pareiasaur assemblage. That may be true, but I suspect that this may be a case of a local fauna only that may have spread as the opportunity presented itself. It may represent a refugium too.

They also suggest that Russia may have a contiguous Upper Permian to Lower Triassic geological set of stages.

More later.