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.

Helms Deep for Metazoan Reef Builders Found From Permian Extinction era Slovenia?

Equatorial Palaeotethys as the last sanctuary for late Permian metazoan reef-builders: New evidence from the Bellerophon Formation of Slovenia

Authors:

Sremac et al

Abstract:

The rise and demise of warm-temperate Permian reefs and biostromes reflect the complex geologic history of this dynamic period. Environments suitable for reef-builders were devastated by the Guadalupian/Lopingian crisis, and Lopingian reefs have only been recorded at a small number of localities. The uppermost Permian limestones of the Bellerophon Formation, on the Vojsko Plateau (Slovenia), contain small, lenticular biostromes within a bioclastic wackestone/packstone lithofacies. The major biostrome builders are medium-sized coralline sponges (Demospongea and Calcarea), encrusted by smaller sponges, tube worms, sessile foraminifera, calcareous algae (Archaeolithoporella) and Shamovella (i.e., Tubiphytes), all of which are typically covered by microbial crusts. The biostromes are characteristically composed of bafflestone and bindstone, incorporating sporadic framestone. Narrow belts of floatstone surround the buildups, and sponge debris is also present in lenses within the mud matrix between metazoan bafflestones. The fossils are generally well-preserved, although the fine skeletal microstructure has been partially recrystallized. Sponges are heavily calcified, and ontogenic thickening of the skeleton can be observed in some encrusters. Framboidal pyrite, forming thin films on the inner walls of sponge chambers, suggests the presence of sulphate-reducing bacteria. These microbial symbionts may have enabled the sponges to survive in the anoxic marine environments of the uppermost Permian. The Changshingian sponge biostromes of the Vojsko Plateau represent the westernmost known occurrence of contemporary metazoan boundstones in the Palaeotethys.

WILDFIRES! in Lopingian Permian Brazil!

Evidence for palaeo-wildfire in the Late Permian palaeotropics — Charcoal from the Motuca Formation in the Parnaíba Basin, Brazil

Authors:

Kauffmann et al

Abstract:

The Permian deglaciation of Gondwana caused a global icehouse/greenhouse transition, leading to increased aridity over large parts of this continent during the Lopingian, contributing to the overall scarcity of plant bearing localities. Despite a continuous increase of reports of fossil charcoal as direct evidence for palaeo-wildfires from Late Palaeozoic deposits, such records from low-latitude and arid to semi-arid areas are still rare. In order to contribute to the discussion about palaeoenvironmental conditions that dominated low latitudinal portions of the globe during that period and especially the occurrence of wildfires, the present contribution reports on charcoal recovered from sandstones from the Andradina Outcrop, Late Permian (Lopingian), Motuca Formation, in the Parnaíba Basin, Northern Brazil. This locality is part of the Northern Tocantins Petrified Forest, which is classified as one of the most important Permian assemblages of permineralized plant remains from warm temperate palaeobiomes of the Southern Hemisphere. The results presented here provide the first evidence for the occurrence of palaeo-wildfires in the western part of the Gondwanan palaeo-tropics during the Lopingian.

Lopingian Permian Niger had a Wildly Seasonal Arid Climate With Water Inundations Like the African Namib Desert and Australian Lake Eyre Basin

Biological and physical evidence for extreme seasonality in central Permian Pangea

Authors:

Looy et al

Abstract:

Climate models indicate increased desertification in the continental interior of Pangea during the Permian, which would have affected the composition of the flora and fauna. We present a multi-proxy paleoenvironmental reconstruction of a terrestrial ecosystem in central Pangea of Lopingian age. The reconstruction is based on biological and physical data from the Moradi Formation, located in the Tim Mersoi Basin, northern Niger. Paleosols and sedimentological evidence indicate that the prevailing climate was semi-arid to very arid with marked intervals of high water availability. Carbon stable isotope data from organic matter and paleosols suggest that both the soil productivity and actual evapotranspiration were very low, corresponding to arid conditions. Histological analysis of pareiasaur bones shows evidence of active metabolism and reveals distinct growth marks. These interruptions of bone formation are indicative of growth rhythms, and are considered as markers for contrasting seasonality or episodic climate events. The macrofossil floras have low diversity and represent gymnosperm-dominated woodlands. Most notable are ovuliferous dwarf shoots of voltzian conifers, and a 25-m long tree trunk with irregularly positioned branch scars. The combined biological and physical evidence suggests that the Moradi Formation was deposited under a generally arid climate with recurring periods of water abundance, allowing for a well-established ground water-dependent ecosystem. With respect to its environment, this system is comparable with modern ecosystems such as the southern African Namib Desert and the Lake Eyre Basin in Australia, which are discussed as modern analogues.

 

Evidence of Anoxic Oceans at in the Lopingian Permian South China

Lopingian (Upper Permian) trace fossils from the northern Penglaitan Section, Laibin, Guangxi, South China and their environmental implications

Authors:

Ding et al

Abstract:

The end-Permian mass extinction has been widely documented to be accompanied with oceanic anoxia, which was considered as one of the most plausible killing mechanisms. However, it is still unclear when anoxia began to occur and how widely affected during the pre-extinction interval. In this study, Lopingian bottom-water oxygen level changes around the Wuchiapingian–Changhsingian boundary (WCB) at the northern Penglaitan section in Guangxi are analysed based on trace fossil assemblages and ichnofabric indices. Detailed bed-by-bed ichnological analyses confirm the presence of trace fossils Chondrites intricatus, C. isp., Palaeophycus isp., Planolites isp. A, P. isp. B, Thalassinoides isp. A, T. isp. B, Trichichnus linearis, Zoophycos isp., and other bioturbational structures. The ichnofabric indices around the WCB are mostly 1-2, but rapidly increase to 4-5 in some short intervals. The distinct fluctuations of ichnofabric indices suggest that the oxygen level of sediments was generally deficient, but the dysoxic or anoxic periods were punctuated by several short oxic intervals. Thus, it can be inferred that the benthic organisms were under secularly environmental stresses around the WCB at the northern Penglaitan section. The anoxic conditions unfavourable for aerobiosis in the deep basin may start in the late Wuchiapingian. However, more sections need to be studied to determine whether this is a local or regional phenomenon.

New Statistical Analysis Suggests Environmental Degradation 1.2 Million Years Before End Permian Extinction

Quantifying the process and abruptness of the end-Permian mass extinction

Authors:

Wang et al

Abstract:

Studies of the end-Permian mass extinction have suggested a variety of patterns from a single catastrophic event to multiple phases. But most of these analyses have been based on fossil distributions from single localities. Although single sections may simplify the interpretation of species diversity, they are susceptible to bias from stratigraphic incompleteness and facies control of preservation. Here we use a data set of 1450 species from 18 fossiliferous sections in different paleoenvironmental settings across South China and the northern peri-Gondwanan region, and integrate it with high-precision geochronologic data to evaluate the rapidity of the largest Phanerozoic mass extinction. To reduce the Signor-Lipps effect, we applied constrained optimization (CONOP) to search for an optimal sequence of first and last occurrence datums for all species and generate a composite biodiversity pattern based on multiple sections. This analysis indicates that an abrupt extinction of 62% of species took place within 200 Kyr. The onset of the sudden extinction is around 252.3 Ma, just below Bed 25 at the Meishan section. Taxon turnover and diversification rates suggest a deterioration of the living conditions nearly 1.2 Myr before the sudden extinction. The magnitude of the extinction was such that there was no immediate biotic recovery. Prior suggestions of highly variable, multi-phased extinction patterns reflect the impact of the Signor-Lipps effect and facies-dependent occurrences, and are not supported following appropriate statistical treatment of this larger data set.

 

Deltavjatia rossicus: a Lopingian Permian Pareiasaur From Russia Redescribed

Anatomy, cranial ontogeny and phylogenetic relationships of the pareiasaur Deltavjatia rossicus from the Late Permian of central Russia

Authors:

Linda A. Tsuji

Abstract:

New material of the pareiasaur Deltavjatia rossicus from the Kotel'nich locality, Kirov Province, Russia, is described in detail. The taxon is characterised by a distinctive pattern of dermal sculpture and the exaggerated embayment of the posterior skull roof, resulting in the dorsal exposure of the braincase. Postcranially, Deltavjatia shares some aspects of its morphology with basal pareiasaurs, including the osteoderm pattern. Features such as the forward-slanting and pointed iliac blade are shared with stratigraphically younger, more derived forms. Well-preserved material of the taxon spans a wide size-range, allowing an assessment of ontogenetic trends. A geometric morphometric analysis of the skull roof of Deltavjatia reveals an allometric increase in snout length and postorbital area, a result that can serve as a basis for examining morphological trends within pareiasaurs. A reassessment of pareiasauromorph relationships, using both parsimony and Bayesian methods of phylogenetic inference, recovers similar topologies in both cases. Four Bayesian analyses were completed, with and without a gamma-shaped parameter and with and without the inclusion of autapomorphies. Despite differing taxon and outgroup selection, the recovered topologies are similar to previous phylogenies of pareiasaurian relationships, with Deltavjatia appearing as a relatively basal taxon.

Fires During the Permian

The burning of Gondwana: Permian fires on the southern continent—A palaeobotanical approach

Authors:

1. André Jasper (a)
2. Margot Guerra-Sommer (b)
3. Abdalla M.B. Abu Hamad (c)
4. Marion Bamford (d)
5. Mary Elizabeth Cerruti Bernardes-de-Oliveira (e, f)
6. Rajni Tewari (g)
7. Dieter Uhl (h, i)

Affiliations:

a. Centro Universitário UNIVATES, Lajeado, Brazil

b. Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil

c. The University of Jordan, Amman, Jordan

d. BPI Palaeontology, University of the Witwatersrand, Johannesburg, South Africa

e. Universidade de Guarulhos, Guarulhos, Brazil

f. Universidade de São Paulo, São Paulo, Brazil

g. Birbal Sahni Institute of Palaeobotany, Lucknow, India

h. Senckenberg Forschungsinstitut und Naturmuseum Frankfurt, Frankfurt am Main, Germany

i. Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls Universität Tübingen, Tübingen, Germany

Abstract:

Fossil charcoal has widely been accepted as a direct indicator for the occurrence of palaeo-wildfires. In Upper Palaeozoic sediments of Euramerica and Cathaysia, records of these remains are relatively common and (regionally and stratigraphically) more or less homogeneously distributed in terrestrial sequences. On the other hand, just a few records have been published for the Permian of Gondwana and only recently has it been demonstrated that macroscopic charcoals are also common here. Most Permian macroscopic charcoal from Gondwana is gymnospermous and has been reported from coal-bearing strata. Macroscopic charcoal occurrences are spread out in different sequences and also in distinct stratigraphic intervals in the Permian [e.g., Paraná Basin (Sakmarian/Artinskian of Brazil), Karoo Basin (Artinskian of South Africa), Damodar Basin (Lopingian of India) and Dead Sea area (Changhsingian of Jordan)]. They range from peri-glacial/post-glacial to warm temperate climatic systems throughout the Permian. Macro- and micro-charcoal occurrences are compared to inertinite incidences to support the pyrogenic origin for these coal macerals and to provide an up to date overview on the known evidences of Permian wildfires on Gondwana in space and time.

This has some serious implications for the paleoatmosphere:  you don't get fires if the oxygen level falls too low.  This goes from the Sakmarian to the Lopingian.