A New Genus of Rhynchonellid Brachiopod from the Lower Triassic of South China and Implications for Timing the Recovery of Brachiopoda After the End-Permian Mass Extinction

A new genus, Meishanorhynchia , is proposed based on new material from the Lower Triassic of the Meishan section, South China. It is of a late Griesbachian age based on both associated biozones (ammonoids and bivalves) and radiometric dates of the intercalated volcanic ash beds. Comparison with both Palaeozoic and Mesozoic–Cenozoic-related genera suggests that it may represent the first radiation of progenitor brachiopods in the aftermath of the end-Permian extinction. The lowest brachiopod horizon that contains the genus is estimated to be about 250.1 ± 0.3 Ma. This implies that the initial stage of recovery of Brachiopoda in the Early Triassic was probably about 1.3 ± 0.3 myr after the major pulse of the end-Permian mass extinction (dated as 251.4 ± 0.3 Ma). This is in agreement with Hallam's expectancy that biotic recovery typically begins within one million years or so of major mass extinctions, in contrast to current views on the end-Permian extinction event which propose that the recovery of most if not all biotic groups in the Early Triassic was severely delayed and only began about five million years after the end-Permian extinction.     

Larval ecology and morphology in fossil gastropods

The shell of marine gastropods conserves and reflects early ontogeny, including embryonic and larval stages, to a high degree when compared with other marine invertebrates. Planktotrophic larval development is indicated by a small embryonic shell (size is also related to systematic placement) with little yolk followed by a multiwhorled shell formed by a free‐swimming veliger larva. Basal gastropod clades (e.g. Vetigastropoda) lack planktotrophic larval development. The great majority of Late Palaeozoic and Mesozoic ‘derived’ marine gastropods (Neritimorpha, Caenogastropoda and Heterobranchia) with known protoconch had planktotrophic larval development. Dimensions of internal moulds of protoconchs suggest that planktotrophic larval development was largely absent in the Cambrian and evolved at the Cambrian–Ordovician transition, mainly due to increasing benthic predation. The evolution of planktotrophic larval development offered advantages and opportunities such as more effective dispersal, enhanced gene flow between populations and prevention of inbreeding. Early gastropod larval shells were openly coiled and weakly sculptured. During the Mid‐ and Late Palaeozoic, modern tightly coiled larval shells (commonly with strong sculpture) evolved due to increasing predation pressure in the plankton. The presence of numerous Late Palaeozoic and Triassic gastropod species with planktotrophic larval development suggests sufficient primary production although direct evidence for phytoplankton is scarce in this period. Contrary to previous suggestions, it seems unlikely that the end‐Permian mass extinction selected against species with planktotrophic larval development. The molluscan classes with highest species diversity (Gastropoda and Bivalvia) are those which may have planktotrophic larval development. Extremely high diversity in such groups as Caenogastropoda or eulamellibranch bivalves is the result of high phylogenetic activity and is associated with the presence of planktotrophic veliger larvae in many members of these groups, although causality has not been shown yet. A new gastropod species and genus, Anachronistella peterwagneri, is described from the Late Triassic Cassian Formation; it is the first known Triassic gastropod with an openly coiled larval shell.     

Olenekian (Early Triassic) bivalves from the Salt Range and Surghar Range,Pakistan

Abstract: Based on newly collected material from the uppermost Smithian and lower to middle Spathian (Olenekian, Lower Triassic) of the Salt Range and Surghar Range (Pakistan), 15 bivalve species belonging to 11 genera are described, including two new genera, Eobuchia and Dimorphoconcha, and one new species, Palaeoneilo? fortistriata. Eobuchia gen. nov. is placed in a new subfamily, the Eobuchiinae, which differs from the Buchiinae in having an almost planar and only moderately inclined or offset right anterior auricle. Inclination of the right anterior auricle is proposed as a synapomorphy of the revised suborder Monotidina, which includes the Buchiidae, Monotidae, Oxytomidae and, tentatively, the Dolponellidae. The Pseudomonotidae, Chaenocardiidae and Claraiidae are discussed as candidate ancestors of the Monotidina. Dimorphoconcha gen. nov., provisionally placed in the Limidae, is a morphologically unusual genus characterized by a globose shell centre and a strongly plicate fringe. Permophorus costatus, which was previously known exclusively from Permian strata, is reported from the Spathian of the Surghar Range. This record extends the range of P. costatus for at least 8 Myr and makes it the first reported Lazarus species, with an outage of more than 2 Myr after the end‐Permian mass extinction. Ten of 15 species recognized in this study have not been reported from other regions, which may indicate increasing provincialism towards the end of the Early Triassic, or, alternatively, reflect the still insufficient knowledge of benthic faunas from the epoch that followed the greatest crisis in the history of life.     

Lystrosaurus species composition across the Permo–Triassic boundary in the Karoo Basin of South Africa

Lystrosaurus is one of the few therapsid genera that survived the end-Permian mass extinction, and the only genus to have done so in abundance. This study identifies which species of Lystrosaurus have been recovered from Permian and Triassic strata to determine changes in the species composition across the Permo–Triassic (P–T) boundary in the Karoo Basin of South Africa. Data generated from museum collections and recent fieldwork were used to stratigraphically arrange a total of 189 Lystrosaurus specimens to determine which species survived the extinction event. Results reveal that L. curvatus and L. maccaigi lived together on the Karoo floodplains immediately before the extinction event. L. maccaigi did not survive into the Triassic in South Africa. L. curvatus survived, but did not flourish and soon became extinct. Two new species of Lystrosaurus , L. murrayi and L. declivis , appeared in the Early Triassic. It is possible that L. murrayi and L. declivis occupied different niches to L. maccaigi and L. curvatus , and had special adaptations that were advantageous in an Early Triassic environment. We suggest that L. maccaigi may be used as a biostratigraphic marker to indicate latest Permian strata in South Africa and that, in support of previous proposals, the genus Lystrosaurus should not be used as a sole indicator of Triassic-aged strata. Our field data also show that L. curvatus may be regarded as a biostratigraphic indicator of the P–T boundary interval.     

Two new species of the pinnate microsporophyll Pramelreuthia from the upper Triassic of the southwestern United States

Two new species of the enigmatic gymnosperm microsporophyll Pramelreuthia, found in the Upper Triassic Chinle Formation at five localities in the southwestern United States, provide significant new evidence on key morphological characters of the genus and extend its known geographical range. These new fossils also demonstrate that the genus was polytypic and reveal the plant megafossil sources for several common and geographically widespread dispersed Upper Triassic microfossil taxa. The genus Pramelreuthia, which until this study was known only from a single specimen from the Upper Triassic of Austria, is a planar pinnate structure consisting of a slender naked axis bearing stalked synangia in opposite to subopposite pairs. Synangia of all three species of Pramelreuthia are oval to subrectangular in lateral view and are composed of two adpressed flattened valves each of which contains up to 20 or more elongate, subcylindrical, tapered sporangia that bear nonstriate bisaccate pollen. Pramelreuthia yazzi sp. nov. is slightly smaller than the type species P. haberfelneri, and its synangia contain pollen generally similar in morphology and size to several species of the dispersed pollen taxon Pityosporites, including P. chinleana, P. oldhamensis, and P. devolvens. Pramelreuthia dubielii sp. nov. is much larger than the other two species; its synangia contain pollen similar to the dispersed pollen species Protodiploxypinus americus.     

Late Triassic (Late Norian) gastropods from the Wallowa Terrane (Idaho,USA)

A diverse Late Triassic (Late Norian) gastropod fauna is described from the Mission Creek Limestone of the Wallowa terrane (Idaho, USA). Sample standardization by rarefaction analysis indicates that the fauna is even more diverse than the Late Triassic gastropod fauna from the Pucara Formation (Peru) which represents the most diverse gastropod fauna from South America. The gastropod fauna consists of 66 species; several genera are reported for the first time from North America. A high percentage of the species are highly ornamented and several have distinct siphonal canals. This suggests that the appearance of truly Mesozoic elements among the gastropods began before the Mesozoic Marine Revolution in other clades. The fauna is dominated by high-spired strongly ornamented procerithiids, a group more characteristic for the Jurassic. Comparison of the present fauna and the Iranian Nayband Formation gastropod fauna show that the procerithiids underwent a first global radiation in the Late Triassic. The high number of new species in this fauna suggests that sampling of Late Triassic gastropod faunas is still incomplete and hinders palaeobiogeographic considerations. Previous suggesions that gastropod faunas from the Wallowa and Wrangellia terranes resemble each other and are distinct from those of Alexander, Chulitna, and Farewell terranes are basically corroborated. The gastropod fauna of the Mission Creek Limestone differs considerably from that of the western and central Tethys but shares several taxa with the Late Triassic gastropod fauna of the Pucara Formation in Peru. Thus, the Hispanic corridor was probably not present in the Norian but opened only in the Early Jurassic. The subfamily Andangulariinae is introduced and placed in the Zygopleuridae. The generaSpiniomphalus, Nodoconus, Gudrunella, Blodgettella, Idahospira, andSiphonilda and the subgenusCryptaulax (Wallowax) are introduced. 27 species are erected. A lectotype is designated forCryptaulax rhabdocolpoides Haas, 1953.      

New data from Oman indicate benthic high biomass productivity coupled with low taxonomic diversity in the aftermath of the Permian–Triassic Boundary mass extinction

A new Early Triassic marine fauna is described from an exotic block (olistolith) from the Ad Daffah conglomerate in eastern Oman (Batain), which provides new insights into the ecology and diversity during the early aftermath of the Permian–Triassic Boundary mass extinction. Based on conodont quantitative biochronology, we assign a middle Griesbachian age to the upper part of this boulder. It was derived from an offshore seamount and yielded both nektonic and benthic faunas, including conodonts, ammonoids, gastropods and crinoid ossicles in mass abundance. This demonstrates that despite the stratigraphically near extinction at the Permian–Triassic Boundary, Crinoidea produced enough biomass to form crinoidal limestone as early as middle Griesbachian time. Baudicrinus, previously placed in Dadocrinidae, is now placed in Holocrinidae; therefore, Dadocrinidae are absent in the Early Triassic, and Holocrinidae remains the most basal crown‐group articulates, originating during the middle Griesbachian in the Tethyan Realm. Abundant gastropods assigned to Naticopsis reached a shell size larger than 20 mm and provide another example against any generalized Lilliput effect during the Griesbachian. Whereas the benthic biomass was as high as to allow the resumption of small carbonate factories, the taxonomic diversity of the benthos remained low compared to post‐Early Triassic times. This slow benthic taxonomic recovery is here attributed to low competition within impoverished post‐extinction faunas.     

Impact of the Late Triassic mass extinction on functional diversity and composition of marine ecosystems

Mass extinctions have profoundly influenced the history of life, not only through the death of species but also through changes in ecosystem function and structure. Importantly, these events allow us the opportunity to study ecological dynamics under levels of environmental stress for which there are no recent analogues. Here, we examine the impact and selectivity of the Late Triassic mass extinction event on the functional diversity and functional composition of the global marine ecosystem, and test whether post‐extinction communities in the Early Jurassic represent a regime shift away from pre‐extinction communities in the Late Triassic. Our analyses show that, despite severe taxonomic losses, there is no unequivocal loss of global functional diversity associated with the extinction. Even though no functional groups were lost, the extinction event was, however, highly selective against some modes of life, in particular sessile suspension feeders. Although taxa with heavily calcified skeletons suffered higher extinction than other taxa, lightly calcified taxa also appear to have been selected against. The extinction appears to have invigorated the already ongoing faunal turnover associated with the Mesozoic Marine Revolution. The ecological effects of the Late Triassic mass extinction were preferentially felt in the tropical latitudes, especially amongst reefs, and it took until the Middle Jurassic for reef ecosystems to fully recover to pre‐extinction levels.     

An unusually diverse mollusc fauna from the earliest Triassic of South China and its implications for benthic recovery after the end-Permian biotic crisis

A single carbonate coquinoid lens from the Griesbachian (Early Triassic) of Shanggan, South China, yielded 11 bivalve species described in this study in addition to four gastropod and one ammonoid species reported elsewhere. This makes the Shanggan fauna one of the richest mollusc faunas from the early post-extinction interval after the end-Permian mass extinction event. Four of the present genera are long-term survivors, five are holdovers that went extinct at the end of the Griesbachian or later in the Early Triassic, and seven first appear in the Griesbachian. Three new bivalve species are described: Myalinella newelli nov. sp., Scythentolium scutigerulus nov. sp., and Eumorphotis shajingengi nov. sp. The genus Astartella, previously assumed to have vanished at the end of the Permian, is reported for the first time from the Early Triassic, which also removes Astartidae from Early Triassic Lazarus taxa. The small growth size of the Astartella specimens supports an earlier hypothesis that many of the Early Triassic Lazarus taxa did not survive in unknown refuges but were simply overlooked due to the scarcity of easily observable large-sized specimens. Ecologically, a comparatively high proportion of infaunal bivalve species (4/11) is remarkable for the early post-extinction interval, supporting the impression of a relatively advanced recovery state. Moreover, abundance-data of the bivalve-gastropod community reveal a remarkably low dominance index (D = 0.17) that is suggestive for advanced recovery and stable environmental conditions. It is proposed that the Shanggan fauna represents a late Griesbachian benthic recovery event that coincided with the appearance of similarly diverse benthic faunas in Oman and Primorye. A high proportion of genera that have previously not been reported from the Early Triassic indicate that the prevalence of poor preservation conditions is a major obstacle in identifying early phases of recovery from the greatest crisis in the history of metazoan life. The early recovery of benthic faunas reported in this study questions previous claims of a prolonged lag phase as a consequence of the extraordinary extinction magnitude or the persistence of adverse environmental conditions.     

Conodonts from the Early Triassic microbialite of Guangxi (South China): implications for the definition of the base of the Triassic System

We describe a new Early Triassic (Griesbachian) succession of conodont faunas from a high‐resolution sampling of the basal Early Triassic microbial limestone and the base of the overlying unit at the Wuzhuan section (Nanpanjiang Basin, Guangxi, South China). The microbial limestone records the earliest phase of the Early Triassic biotic recovery after the end‐Permian mass extinction. For the first time, rich conodont faunas are reported from within the microbialite. The faunas from Wuzhuan are largely dominated by anchignathodontids, including several Isarcicella species, which were previously documented only from strata above the microbialite. A total of 14 conodont species assigned to three genera is recorded from the Wuzhuan section. Starting from the base of the microbialite upwards, several species are sequentially added to the conodont assemblage. The alpha diversity peaks at the top of the microbialite. The conodont record in the considered microbialite interval at Wuzhuan is presumably unaffected by local ecological changes. It therefore more likely represents an evolutionary rather than an ecological pattern. We compare the Wuzhuan's conodont record with a well‐supported phylogenetic model and suggest that the sequence of first occurrences at Wuzhuan is the closest to the ‘true’ sequence of evolutionary events that took place during this Griesbachian radiation of anchignathodontids. Based on comparisons with the GSSP section at Meishan, we suggest further that the first occurrence of Hindeodus parvus in Meishan does not correspond to its first appearance datum.     

Taxonomy of the proterosuchid archosauriforms (Diapsida: Archosauromorpha) from the earliest Triassic of South Africa,and implications for the early archosauriform radiation

Proterosuchidae is one of the first clades of Archosauriformes (archosaurs and closely related species) to appear in the fossil record, with the richest sample of the group coming from the Lystrosaurus Assemblage Zone (earliest Triassic) of South Africa. Four nominal proterosuchid species were described from South Africa during the twentieth century (Proterosuchus fergusi, Chasmatosaurus vanhoepeni, Chasmatosaurus alexanderi and Elaphrosuchus rubidgei), but interpretations of their taxonomy have been widely disparate. The most recent taxonomic revision concluded that P. fergusi is the only valid species and that the other nominal species are junior subjective synonyms of this taxon. This proposal was based on the interpretation that anatomical differences between the nominal species could be explained as a result of ontogenetic changes and/or post‐mortem deformation. The recent discoveries of multiple new South African proterosuchid specimens provide an impetus to revisit their taxonomy. Based upon a comprehensive re‐examination of all known specimens, as well as examination of other proterosuchid taxa in collections worldwide, we conclude that the holotype of Proterosuchus fergusi is undiagnostic. As a result, we propose a neotype (RC 846) for the species. ‘Chasmatosaurus vanhoepeni’ and ‘Elaphrosuchus rubidgei’ are considered subjective junior synonyms of P. fergusi. ‘Chasmatosaurus’ alexanderi is considered a valid species, for which we propose the new combination P. alexanderi comb. nov. A third species, P. goweri sp. nov., is erected on the basis of a single specimen (NMQR 880). All three species recognized here are taxonomically distinct from a previously described archosauriform maxilla from the lower Lystrosaurus AZ. As a result, we recognize a minimum of four archosauriform species following the Permo‐Triassic mass extinction in South Africa. Our results suggest a greater species richness of earliest Triassic archosauriforms than previously appreciated, but that archosauriform morphological disparity remained low and did not expand until the late Early Triassic – early Mid‐Triassic.     

Two new species of Saurichthys (Actinopterygii: Saurichthyidae) from the Middle Triassic of Monte San Giorgio,Switzerland, with implications for character evolution in the genus

Saurichthys, characterized by a long slender body and an elongated rostrum, is one of the most iconic genera of Late Paleozoic–Early Mesozoic fishes. The genus was particularly speciose in the Triassic, with a global distribution in both marine and freshwater habitats. Here, we describe two new species from the Middle Triassic Besano Formation of Monte San Giorgio, Switzerland, Saurichthys breviabdominalis sp. nov. and Saurichthys rieppeli sp. nov. S. breviabdominalis is characterized by a proportionately long operculum, short abdominal region and rib‐like mid‐lateral scales, whereas S. rieppeli is divergent from other Middle Triassic saurichthyids in the block‐like haemal arches, fringing fulcra on the pelvic and unpaired fins, and reduction of the squamation to a single row in the abdominal region. Phylogenetic analysis places S. rieppeli in a basal position relative to congeners from the Alpine Triassic, and supports previous hypotheses regarding the convergent evolution of reduced squamation within saurichthyids. S. breviabdominalis forms a monophyletic group with species from the same locality, suggesting divergence in sympatry. This finding has implications for our understanding of disparity and character evolution in saurichthyid fishes, as well as ecomorphological divergence and resource partitioning between closely related fishes in Triassic marine ecosystems. © 2015 The Linnean Society of London     

Revision ofSemionotus bergeri Agassiz, 1833 (Upper Triassic, Germany), with comments on the taxonomic status ofSemionotus (Actinopterygii, Semionotiformes).

Semionotus bergeri Agassiz, 1833, from the Upper Triassic (Carnian) of southern Germany, the type species ofSemionotus, is here described in detail for the first time, including so far unstudied material in the Naturkunde-Museum Coburg, which allows a fairly complète reconstruction of this fish. The species is diagnosed by the présence of long frontals, about 4 times longer than wide, with antorbital lateral processes, 6–7 posterior infraorbitals, infraorbital at the posteroventral corner of the orbit notably larger than adjacent ones, infraorbitals at the posterior border of the orbit being as deep as long, and the middle élément anteroventrally expanded, dorsal fin base about two times the anal fin base.S. elegans from the Late Triassic-Early Jurassic of the Newark Supergroup in North America, is so far the best know species ofSemionotus and is the only species of this genus that has been included in phylogentic analyses. However, the comparison ofS. bergeri with other proposed speciesof Semionotus, such asS. elegans, and other semionotids casts doubt on the monophyly of this genus as currently understood, since these species exhibit a mosaic distribution of characters.      

Diversity and palaeoecology of a highly diverse Late Triassic marine biota from the Cassian Formation of north Italy

A sample of marine invertebrates from the Late Triassic Cassian Formation (north Italy) yielded one of the most diverse Early Mesozoic fossil assemblages ever reported (c. 170 species). The assemblage was found in basin clays, but was transported from nearby carbonate platforms as indicated by fragmentation, microbial encrustation and the presence of coated grains and ooids. Most of the specimens are small (< 1 cm) reflecting both, small adult sizes and size sorting during transport. Rarefaction analysis suggests that diversity of surface collection and bulk sampling is the same. However, rank abundance, species richness and taxonomic composition differ strongly according to sampling method. Low‐grade lithification of the sediments is the main reason that high diversity can be recognized, because it facilitates disaggregation and finding of small molluscs. Sample standardization shows that the studied assemblage is much more diverse than known Early Triassic assemblages. However, its diversity is similar to that of Anisian assemblages. This suggests that recovery from the end‐Permian mass‐extinction was quite advanced in the Middle Triassic and alpha‐diversity remained high until the Late Triassic. According to current models, Early Triassic and Anisian faunas match the niche overlap phase of recovery during which diversity is built up by increasing alpha‐diversity, whereas beta‐diversity rises slowly. Subsequently, habitat width of species contracts because of increasing competition, making beta‐diversity the principal drive of overall diversity increase. The diversity pattern of various Late Triassic Cassian associations meets the predictions for the transition from the niche overlap to the habitat contraction phase.: Triassic, Cassian Formation, palaeoecology, diversity, mollusc dominance.     

New dasycladalean algae from the Middle Norian (Upper Triassic) of northern Italy (Mt. Pramaggiore, Carnic Prealps)

In the Eastern Southern Alps of northern Italy (Carnic Prealps, Friuli region), the shallow-water carbonate platform deposits of the Dolomia Principale Fm. (Norian–Rhaetian, Upper Triassic) show best-preserved platform to basin facies transition. The palaeontological study of an algal-rich level recovered from the platform margin facies (Mt. Pramaggiore) has displayed a very interesting association of Dasycladales. Two new genera (Bystrickyella and Elliottporella) and four new species (Bystrickyella ottii, Elliottporella morelloae, Palaeodasycladus lorigae and Holosporella conradii) have been described. These new data suggest that the Norian represents a period of turnover in the evolutionary history of the green algae community. This stage, placed between two extinctions, end-Ladinian and end-Norian, is here interpreted as a re-organization period of the evolutionary schemes of Dasycladales. The new lineages originated in the Norian developed further and characterized the Early Jurassic scenery. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A new species of Leptocycas (Zamiaceae) from the Upper Triassic sediments of Liaoning Province,China

A new cycad,Leptocycas yangcaogouensis sp.nov.,was found in sediments from the Late Triassic in western Liaoning,China.The pinnately compound leaves(Pseudoctenis type)are screwed in a crown on the stem top.The leaflets are linear,with parallel veins and decurrent bases on the rachis.The leaf bases are persistent.The cataphylls intermix with the leaves.The female cone is ovoid in shape.The characteristics of the new plant are more similar to those of Leptocycas gracilis,a Triassic cycad from North America,but the new species differs from L.gracilis in the size of its stem(7–8 vs.3–5 cm in diameter,respectively),leaves(length×width 100×16 vs.30×7 cm,respectively)and leaf density along the stem(4–6 vs.1–2 bases/1 cm length,respectively).Both L.gracilis and L.yangcaogouensis,having leaves of the Pseudoctenis type,show a closer relationship to the extant Dioon of Zamiaceae.The present study provides evidence for the origin of the genus Dioon,which may have come from Leptocycas plants of the Triassic.It would be assumed that the extent cycads in Zamiaceae originate from the pteridosperms in the Late Paleozoic and have evolved through the stage of L.gracilis and L.yangcaogouensis in Late Triassic,and reaching the extant Dioon.     

Triassic turtle tracks and the origin of turtles

Turtle (Testudines) tracks, Chelonipus torquatus, reported from the early Middle Triassic (Anisian) of Germany, and Chelonipus isp. from the late Early Triassic (Spathian) of Wyoming and Utah, are the oldest fossil evidence of turtles, but have been omitted in recent discussions of turtle origins. These tracks provide significant clues as to how early the turtle Bauplan originated. Turtle trackways are quite distinctive: the manus and pes form tracks nearly parallel to the midline and indicate an unusually wide gait in which the trackway width is nearly equal to the stride length. These tracks do not fit what would be expected to be made by Triassic Pappochelys or Odontochelys, a supposed prototurtle and an early turtle, respectively. In contrast, these tracks are consistent with what would be expected from the Triassic turtles Proganochelys and Palaeochersis. The features inferred to be present in Triassic turtle tracks support the notion that Odontochelys is a derived aquatic branch of the turtle stem lineage rather than the ancestral state of all turtles. Chelonipus also resembles the Permian track Pachypes dolomiticus, generally assigned to a pareiasaur trackmaker. These revelations highlight the need to consider all available evidence regarding turtle origins, rather than just the body fossils.     

Dasycladalean green algae from the Upper Triassic of Mt. Rotonda (Verbicaro Unit, Calabria-Lucania Border, Southern Italy)

Summary A rich and diverse dasycladalean algae association is described from the Upper Triassic succession of Mt. Rotonda (Calabria-Lucania border, Southern Italy). This association consists of:Neoteutloporella rajkae n.sp.,Griphoporella bechst?dti n.sp.,Physoporella zamparelliae n.sp.,Spinaporella andalusica Flügel & Flügel-Kahler, 1984,S.? granadaensis Flügel & Flügel-Kahler, 1984,Chinianella? sp.,Gyroporella sp.,Griphoporella? sp. andPhysoporella aff.leptotheca. Neoteutloporella rajkae n.sp. is characterised by an undulated calcareous skeleton with short acrophore primary laterals bearing a tuft of 4–6 elongate, segmented, trichophore secondary laterals. This species allows to extend back to the Upper Triassic the stratigraphic range of the genusNeoteutloporella, previously known only from Upper Jurassic levels. Griphoporella bechst?dti n.sp. has a cylindrical calcareous skeleton and primary laterals only, consisting of a thin proximal part followed by a swollen portion that pinches out distally and finally opens outward with a cup-like swelling. Physoporella zamparelliae n.sp. is characterised by a calcareous skeleton made by partly welded thin individual sheaths enclosing the laterals. The laterals are piriferous, vertically compressed, roughly triangular both in vertical and in verticillar section. In some specimens they end with a spine-like thin apophysis. This species confirms that the typical Middle Triassic genusPhysoporella survived up into the Norian. The dasycladalean algal association of the Norian of Mt. Rotonda shows some similarities with the algal association found in the Upper Triassic of the Betic Cordillera whereas it is markedly different from the rich association occurring in the Upper Triassic of Sicily and of the Northern Calcareous Alps. This pattern is coupled with a different composition of the platform margin communities: microbial/serpulids bioconstructions in the Upper Triassic of the Calabria-Lucania border and of Alpujarridevs. Dachstein-type reefs in Sicily and the Northern Calcareous Alps. This indicates that the palaeoceanographic and palaeogeographic conditions controlled both the development of the different platform margin and of the different algal assemblages.     

Palaeoecological significance of a new Griesbachian (Early Triassic) gastropod assemblage from Oman

A new Early Triassic (Griesbachian) gastropod fauna from the Al Jil Formation of Oman is described. Early Triassic faunas from elsewhere (e.g. the Italian Dolomites and the western USA) are typically of low diversity and high dominance, usually attributed to environmental stress in the immediate aftermath of the end-Permian mass extinction event. The new Oman fauna has, by contrast, relatively high diversity, low dominance and a more even spread of individuals between taxa. It is the most diverse Griesbachian fauna known to date. This is attributed to the favourable (i.e. well-oxygenated) conditions under which the fauna lived. This uncharacteristic Griesbachian gastropod fauna demonstrates that, in the absence of oceanic anoxia, biotic recovery after the end-Permian extinction event may occur surprisingly quickly (within one conodont zone). The fauna is also partially silicified, which has increased its preservation potential relative to other Griesbachian gastropod assemblages. However, only one reappearing Lazarus genus is present in the Oman fauna. This suggests that there was some other control on the abundance of Lazarus genera at this time, other than the absence of silicified faunas as previously suggested.     

Annalepis, a pioneering lycopsid genus in the recovery of the Triassic land flora in South China

Fossil plants are scarce in the Earliest Triassic marine deposits of western Guizhou and eastern Yunnan. Only Annularia shirakii, Lobatannularia sp., Paracalamites stenocostatus, Gigantopteris sp., Pecopteris sp. were reported from the base of the Kayitou Formation dated as Early Induan by marine fauna. Recently, we discovered numerous representatives of the genus Annalepis in the same Lowermost Triassic beds: A. latiloba, A. brevicystis, A. angusta, Annalepis spp. occur associated with a basal Triassic marine fauna. This discovery fills the biostratigraphic gap between the Late Permian “Gigantonoclea guizhouensis-Ullmannia cf. bronnii-Annularia pingloensis” and the late Lower Triassic “Neuropteridium–Albertia–Voltzia” assemblages reported from South China. It represents an important datum dealing with the very beginning of a new terrestrial flora installation after the Permian flora disappearance following the Permian–Triassic boundary mass extinction. This “starting point” of a new vegetal cover in South China is to be taken into account in reconstructing through space and time the settlement process of the Mesozoic floristic provinces.