Permian

A NEW SPECIES OF SCLEROCEPHALUS (TEMNOSPONDYLI: STEREOSPONDYLOMORPHA) FROM THE EARLY PERMIAN OF THE BOSKOVICE BASIN (CZECH REPUBLIC)

by J.Sébastien Steyer

A new species of the temnospondyl tetrapod, Sclerocephalus stambergi n. sp., is described from
the early Permian... more A new species of the temnospondyl tetrapod, Sclerocephalus stambergi n. sp., is described from
the early Permian deposits of the Boskovice Basin in Moravia (Czech Republic). The length of the skull of the
only known specimen is about 50 mm. Characters including the well-ossified quadrate, septomaxilla and
scapulocoracoid, presence of the maxilla-nasal suture and a free posterolateral margin of the supratemporal suggest
an early adult age. This new species of Sclerocephalus is distinguished from the others on the basis of the following
characters: nasal and maxillary processes of the premaxilla of equal width; absence of the alary process of the
premaxilla; distinct pointed process on the lacrimal between the maxilla and jugal; narrow interclavicle; and very
peculiar tabular presenting a quadrangular, plate-like process extending from its posterolateral portion, an almost
right angle between its lateral and posterior margins, and a long posteromedial process. The new species represents
the smallest and possibly the most basal Sclerocephalus species. The specimen described here sheds new light on the
anatomy and taxonomy of Sclerocephalus. It completes the biodiversity of the tetrapod fauna from the Boskovice
Basin, and our knowledge on the evolution of the European Paleozoic temnospondyls.

On the use of osteoderm features in a phylogenetic approach on the internal relationships of the Chroniosuchia (Tetrapoda: Reptiliomorpha)

by Michael Buchwitz

Buchwitz, M. C. Foth, I. Kogan, and S. Voigt. in press. On the use of osteoderm features in a phylogenetic approach on the internal relationships of the Chroniosuchia (Tetrapoda: Reptiliomorpha). Palaeontology. [DOI: 10.1111/j.1475-4983.2012.01137.x]

Abstract:  Chroniosuchians are an enigmatic Permian to Triassic group of crocodile-like basal tetrapods. Their... more Abstract:  Chroniosuchians are an enigmatic Permian to Triassic group of crocodile-like basal tetrapods. Their conspicuous dorsal osteoderm systems include most of the group’s yet documented postcranial morphological variability but have hardly been considered in cladistic approaches. Aiming at the clarification of the internal relationships of the Chroniosuchia, we have carried out a parsimony analysis including, among others, 23 morphological and osteohistological osteoderm characters and 12 chroniosuchian taxa. According to the most parsimonious trees, taxa usually referred to Chroniosuchidae form a paraphyletic succession with Madygenerpeton pustulatus and Chroniosaurus dongusensis as the basalmost chroniosuchians and Uralerpeton tverdochlebovae as the sister group of Bystrowianidae (hypothesis A). However, the concurrent hypothesis of a basal split into monophyletic subtaxa Chroniosuchidae and Bystrowianidae (hypothesis B) is only slightly less parsimonious and supported by an alternative analysis which includes embolomeres as the only reptiliomorph outgroup. Searching for the better hypothesis, we compare the respective order of branching to the order of first occurrences in the fossil record, demonstrating that hypothesis A provides a better stratigraphic fit than hypothesis B. Accordingly, the last common ancestor of the yet known chroniosuchians had a series of broad complexly interlocking ‘chroniosuchid’ osteoderms that served as a protection carapace apart from supporting the trunk during terrestrial locomotion. The later evolution of chroniosuchian carapaces was marked by a stepwise increase in flexibility and size reduction, which resulted in a loss of protective function and in a reduction in trunk support function. The flexibility increase is paralleled by the evolution of the Crocodylomorpha whose extant members do not possess as extensively interlocking osteoderm systems as some of their Mesozoic relatives.

The Late Palaeozoic trilobites of Iran and Armenia and their palaeogeographical significance.

by Rudy Lerosey-Aubril

LEROSEY-AUBRIL, R. in press. The Late Palaeozoic trilobites of Iran and Armenia and their palaeogeographical significance. Geological Magazine.

The Iranian territory is composed of a mosaic of tectonic units, several of which underwent in the Permian and... more The Iranian territory is composed of a mosaic of tectonic units, several of which underwent in the Permian and Triassic periods a migration from northern Gondwana to southern Laurussia associated with the opening of the Neo-Tethys Ocean. Although this broad outline of Permo-Triassic palaeogeographical evolution of Iranian microplates is now widely accepted, the individual timing of migration of these blocks, and their biogeographical relationships, remain insufficiently known. Here I review the Late Palaeozoic record of trilobites in Iran and Armenia, and discuss their palaeobiogeographical affinities in an attempt to shed light on the Permian palaeogeographical evolution of Iranian and Armenian terranes. Seven Iranian or Armenian localities, representative of five tectonic units, have yielded Carboniferous and Permian trilobites. Ten species are recognized, including two new taxa, Persia praecox gen. nov. sp. nov. and Pseudophillipsia (s.l.) parvizii sp. nov. P. praecox is the only Carboniferous (Tournaisian) species. The others are Wordian to Wuchiapingian in age and can be separated into three morphological groups, probably representing clades. One is composed of representatives of Acropyge, while the two others (armenica-group and paffenholzi-group) comprise species of Pseudophillipsia. Only P. (s.l.) parvizii sp. nov. from the Zagros Mountains (Arabian Plate) is not attributed to one of these groups. The distribution of trilobites in Iran and Armenia strongly suggests that the Alborz, Central Iran, and Transcaucasia microplates represented a single biogeographical unit in the Middle and Late Permian. Special relationships of this biochore with South China can also be stressed.

A new large caseid (Synapsida, Caseasauria) from the Permian of Rodez (France), including a reappraisal of "Casea" rutena Sigogneau-Russell & Russell, 1974

by Jocelyn Falconnet

Reisz R.R., Maddin H.C., Fröbisch J. & Falconnet J. 2011.
Geodiversitas 33(2): 227-246.

The description of a new large caseid, Ruthenosaurus russellorum n. gen., n. sp. from the Permian (upper Cisuralian to... more The description of a new large caseid, Ruthenosaurus russellorum n. gen., n. sp. from the Permian (upper Cisuralian to lower Lopingian) of the Rodez Basin, France, is based on a partial postcranial skeleton that was initially collected at the same time as the holotype of “Casea” rutena Sigogneau-Russell & Russell, 1974. Despite its distinctly larger size than “C.” rutena, the holotype of Ruthenosaurus n. gen. clearly represents an immature individual, as shown most clearly by the lack of fusion of the neural arches to their respective vertebral centra and incomplete ossification of the ends of the limb elements, including the absence of an ossified olecranon on the ulna. Nonetheless, Ruthenosaurus n. gen. is diagnosed by several autapomorphic characters, including dorsal vertebrae with anteriorly tilting neural spines and a diamond-shaped outline in transverse section, a first sacral rib with a dorsoventrally expanded distal head, and a low iliac blade with a poorly developed anterior process. The new taxon is further distinguishable from the only other known French caseid, “Casea” rutena, by the shape of the distal part of the humerus, including an ectepicondylar notch rather than a fully enclosed foramen, the specific shape of the ulna, and the overall robustness of the specimen. The taxonomic status of “Casea” rutena is discussed and it is concluded that this species should be moved into a new genus named Euromycter n. gen. The occurrence of the large-sized Ruthenosaurus n. gen. in France increases our knowledge about the early diversity of this clade in Europe.

Quantitative approach of diversity and decline in late Palaeozoic trilobites. (PDF available on request)

by Rudy Lerosey-Aubril

LEROSEY-AUBRIL R. & FEIST R. 2012. Quantitative approach of diversity and decline in late Palaeozoic trilobites. In: Talent, J.A. (Ed.), Earth and Life: Global Biodiversity, Extinction Intervals and Biogeographic Perturbations through Time, pp. 535-555. Springer Publishing.

Quantitative data reveal a complex evolution of late trilobite diversity. In the Mid- to early Late Devonian, a series... more Quantitative data reveal a complex evolution of late trilobite diversity. In the Mid- to early Late Devonian, a series of extinction events led to a drastic taxonomic impoverishment. In the Famennian, while only two orders remained, originations started to compensate still high extinction rates marking the onset of a remarkable diversification. Though interrupted by the major Hangenberg turnover, the general diversification trend accelerated in the Tournaisian whilst extinctions became modest. Originations notably diminished during the Viséan and the Serphukovian, making the diversity to step down at the level of the Frasnian. It has never been much higher thereafter, despite a profound restructuring of trilobite communities in the early Pennsylvanian permitting the progressive domination of ditomopygines. After another drop in the Kasimovian a period of stasis occurred with very low diversity levels and almost no renewal. The last diversification burst took place in the Wordian, but it ceased rapidly in the Capitanian when the degradation of environmental conditions started to inhibit originations. Thus, the extinction of the Trilobita at the end of the Permian resulted from the disappearance of merely a handful of genera.

Permian trilobites from Antalya Province, Turkey, and enrollment in Late Paleozoic trilobites.

by Rudy Lerosey-Aubril

LEROSEY-AUBRIL R. & ANGIOLINI L. 2009. Permian trilobites from Antalya Province, Turkey, and enrollment in Late Paleozoic trilobites. Turkish Journal of Earth Sciences, 18(3): 427-448.

Trilobites are a minor component of Permian benthic marine faunas, which explains why they remain poorly known. For... more Trilobites are a minor component of Permian benthic marine faunas, which explains why they remain poorly known. For example, only two specimens have been found in the highly fossiliferous and extensively studied Middle-Upper Permian Pamucak Formation (Antalya Province, Turkey). These two complete enrolled trilobites of Wordian age are described herein. The diagnosis of the subgenus Pseudophillipsia (Nodiphillipsia) Kobayashi & Hamada 1984a is emended and its occurrence outside of eastern Asia is reported for the first time. The second specimen represents a new species, Pseudophillipsia (Carniphillipsia) kemerensis sp. nov. Its discovery in the Wordian of Turkey suggests that Pseudophillipsia (Carniphillipsia) is no less diversified in the Middle Permian than in the Early Permian. Both specimens exhibit a particular enrollment posture, with the anterior part of the pygidium located within the cephalic cavity, while its posterior part is adpressed against the anterior cephalic doublure. The advantages of this style of enrollment are discussed, especially with regards to resistance of the enrolled body to external pressures, and rare examples of similar postures in older trilobites are reported. These two specimens are the first Permian trilobites from Turkey to be described, thus complementing the poor fossil record of these organisms in the Permian of southwestern Asia.

The Inorganic Chemistry of 15 Coal Samples from the Prince Charles Mountains, East Antarctica

by Stephen McLoughlin

Reference:
Chiehowsky, L.A.,Finkelman, R.B., Moore, T.A., Holdgate, G.R., Willett, J.C., McLouglin, S., Drinnan, A.N., 2004. The Inorganic Chemistry of 15 Coal Samples from the Prince Charles Mountains, East Antarctica. In,Bragg,  L.J., Lentz, E.E., Warwick, P.D.,Finkelman, R.B. & Trippi, M.H., eds,Proceedings of the Twentieth Annual Meeting of The Society for Organic Petrology: 2003, Volume 20, Washington D.C. (United States Department of the Interior, U.S. Geological Survey Open File Report 2004-1283), 76-82. (extended abstract)
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Glossopteris - insights into the architecture and relationships of an iconic Permian Gondwanan plant

by Stephen McLoughlin

Reference:
Stephen McLoughlin, S. (in press: 2012) Glossopteris - insights into the architecture and relationships of an iconic Permian Gondwanan plant. Journal of the Botanical Society of Bengal 65, 1-14.
(Proof copy available only)
= 13th J. Sen Memorial Lecture

Almost 200 years after the discovery and formal description of Glossopteris, a widespread fossil gymnosperm of India... more Almost 200 years after the discovery and formal description of Glossopteris, a widespread fossil gymnosperm of India and the southern continents, several key questions remain unanswered about this plant group. Glossopteris achieved iconic status through its use as evidence in support of early concepts of continental drift, but the precise geographic limits of this plant group remain poorly constrained. Glossopterids have been interpreted with a broad range of growth habits, but whole-plant reconstructions via association of normally detached organs are now providing a clearer image of these forest mire plants. Greatest controversy surrounds interpretation of the architecture of glossopterid ovuliferous organs. The many morphogenera established for these fossils require systematic revision but fundamental questions of organ homology between glossopterids and other groups will require careful anatomical investigations of three-dimensionally preserved permineralized fossils. The puzzle of glossopterid growth in polar latitudes in the Permian and the rapid decline of this widespread order throughout Gondwana at the close of the Permian will require high-resolution macrofossil and palynological sampling together with investigations of glossopterid ecological signatures in conjunction with other palaeoenvironmental proxy evidence.

Late Permian palynology of Fossilryggen, Vestfjella, Dronning Maud Land, Antarctica

by Sofie Lindström

Reference:
Lindström, S., 1996. Late Permian palynology of Fossilryggen, Vestfjella, Dronning Maud Land, Antarctica. Palynology 20, 15-48.

Ninety-one samples from three sections at Fossilryggen in the Vestfjella mountain range of Antarctica have been... more Ninety-one samples from three sections at Fossilryggen in the Vestfjella mountain range of Antarctica have been investigated palynologically. Sixty-six taxa are recognized in forty-eight productive samples from two of these sections: the southern section at Fossilryggen and the NW Nunatak section. The palynomorphs have been subjected to contact metamorphosis and display various grades of thermal maturity, ranging in color from light brown to black. They also display various degrees of preservation. Among the spores found are Didecitriletes ericianus, D. uncinatus, Dictyotriletes labyrinthicus (Anderson) comb. nov., Horriditriletes filiformis, Microbaculispora trisina, M. villosa, Osmundacidites wellmanii and Gondisporites raniganjensis. Taeniate and non-taeniate bisaccates are dominant and include Scheuringipollenites ovatus, S. maximus, Vitreisporites pallidus, Protohaploxypinus spp., Striatopodocarpidites spp. and Guttulapollenites hannonicus. Other pollen-grains present are Weylandites lucifer, Praecolpatites sinuosus and Bascanisporites undosus. Although the sections have been interpreted as being deposited in a near-shore marine environment, acritarchs and algae are rare in these assemblages and include the forms Peltacystiavenosa, P. monile, Cymatiosphaera gondwanensis, Leiosphaeridia sp. B and Brazilea scissa. These assemblages are regarded as being of Late Permian age, Kazanian to Tatarian, and are correlated with Upper Stage 5 palynofloras in Australia, and with similar assemblages in Africa and India. Correlations are also made with other Late Permian palynofloras within Antarctica.

Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea

by Juan Carlos Cisneros

A reevaluation of early amniote phylogeny

by Michel Laurin

The evolution of body size, Cope's rule and the origin of amniotes

by Michel Laurin

The osteology and relationships of Tetraceratops insignis, the oldest known therapsid

by Michel Laurin

A reappraisal of Utegenia, a permo-carboniferous seymouriamorph (tetrapoda: batrachosauria) from Kazakhstan

by Michel Laurin

The reptile Macroleter: First vertebrate evidence for correlation of Upper Permian continental strata of North America and Russia

by Michel Laurin

The importance of global parsimony and historical bias in understanding tetrapod evolution. Part II. Vertebral centrum, costal ventilation, and paedomorphosis

by Michel Laurin

Re-evaluation of Cutleria wilmarthi, an Early Permian synapsid from Colorado

by Michel Laurin

The Osteology of Seymouriamorphs and Its Implications for the Origin of Ammiotes

by Michel Laurin

Discussion and reply: The reptile Macroleter: First vertebrate evidence for correlation of Upper Permian continental strata of North America and Russia. Authors' reply

by Michel Laurin

Phylogeny and Apomorphies of Temnospondyls

by Michel Laurin