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Proterochampsids form a clade of archosauriforms endemic to South America, interpreted as the sister-taxon of the crown-group Archosauria. Because of this, aspects of the skull osteology in this group are particularly important to understand the evolutionary radiation of Archosauriformes. The braincase anatomy of archosauriforms was described for several groups, including few proterochampsids. However, paleoneurological studies on basal archosauriforms are scarce, and these were never conducted on proterochampsids, except for few preliminary analyses of Tropidosuchus romeri and Pseudochampsa ischigualastensis. Here we add descriptive information on the braincase and partial endocranial morphology of the type-specimens of the proterochampsids Pseudochampsa ischigualastensis and Tropidosuchus romeri based on CT scans. Reptile Encephalization Quotient (REQ) and olfactory ratios were calculated for the first the time for a proterochampsid, indicating a high olfactory acuity for Tropidosuchus romeri, and suggesting a lifestyle similar to that of living crocodilians. The neurocranial information presented here is important due the scarcity of such data for Proterochampsidae.
The Kiputz IX site has provided one of the best-preserved late Pleistocene bison populations in the southern Pyrenees and has yielded the first almost complete skull of a steppe bison (Bison priscus) in the Iberian Peninsula. This Bison priscus skull is compared on morphological and osteometric grounds with other specimens of steppe bison from Europe and North America. The skull from Kiputz IX falls within the range of the extinct subspecies Bison priscus mediator. Available data support the evidence of three chronological subspecies of Bison priscus (Bison priscus gigas, Bison priscus priscus, and Bison priscus mediator) during the Middle and late Pleistocene.
Calmoniid trilobites of the genus Metacryphaeus Reed include M. tuberculatus (Kozlowski), M. kegeli Carvalho, Edgecombe and Lieberman, M. meloi Carvalho, Edgecombe and Lieberman, M. rotundatus (Kozlowski), M. giganteus (Ulrich), M. convexus (Ulrich), M. curvigena Lieberman, M. branisai Lieberman, M. caffer (Salter), M. australis (Clarke), and M. allardyceae (Clarke). The geographic distribution of this genus comprises areas of Gondwana, including Bolivia, Peru, Brazil, the Falkland Islands, and South Africa. This study reports a new occurrence of M. tuberculatus in the Paraná Basin (Goiás and Paraná states, Brazil), in both the Alto Garças and the Apucarana sub-basins. Metacryphaeus tuberculatus was compared with all Metacryphaeus species and, especially, with M. australis, which also represents a new record for the Paraná Basin. These new records of M. tuberculatus imply a different dispersion interpretation from that which is known through the literature. Metacryphaeus tuberculatus seems to have originated during the Early Devonian and lived in areas such as Bolivia, Peru, and the Apucarana Sub-basin (Paraná Basin, Brazil). The dispersion between these areas is probably related to the Emsian transgression. During the Givetian, the species presumably migrated towards the Alto Garças Sub-basin (Paraná Basin, Brazil) and the Parnaíba Basin. These facts provide an alternative paleogeographic interpretation to that presented by Tropidoleptus Hall and Exaesiodiscus Moore and Jeffords in Gondwana and suggest a different pattern of migration during the Devonian of Brazil.
Ostracods from the Lower Devonian (Lochkovian) of the Argentine Precordillera Basin (upper levels of the Los Espejos Formation and lowermost ones of the Talacasto Formation) were studied. These units represent one of the best Lochkovian stratigraphic records in the Malvinokaffric basins. According to this revision, records of Devonian ostracod faunas in southwestern Gondwana can be extended to older stratigraphic levels. One new genus Suinella and ten species, including five new records (Suinella huarpesi gen. and sp. nov., Amphizona? argentinensis sp. nov., Bollia talacastensis sp. nov., Petrisigmoopsis? rotundum sp. nov. and Pircawayra antiqua sp. nov.) and one reassignment (Thilpsurella aff. T. putea Coryell and Cuskley) were hereby defined. The studied taxonomic assemblage differs from younger Devonian Malvinokaffric ostracod associations by being relatively diverse and composed mainly of drepanelloideans together with metacopids. The association is characterised by species with thin and spiny carapaces, a fact suggesting a relatively deep and low-energy environment below storm wave base. The mixed palaeobiogeographic affinities of the Lochkovian ostracod fauna contrasts with the clear Malvinokaffric signature of the upper Lower—Middle Devonian associations previously recognised in Argentina.
A new genus, Karingbalia is established to accommodate certain eastern Australian glossopterid fertile organs previously assigned to Ottokaria Zeiller emend. Pant et Nautiyal. Karingbalia differs from Ottokaria mainly by the sub-parallel rather than perpendicular orientation of basal peripheral lobes with respect to the receptacle margin. Moreover, Karingbalia ranges from the Artinskian to Changhsingian, whereas Ottokaria sensu stricto is probably confined to the Cisuralian. Two Karingbalia species are recognized: K. inglisensis McLoughlin comb. nov. from the Lopingian of the Bowen and Sydney basins; and K. nychumensis sp. nov. from Artinskian—lower Kungurian strata on the Georgetown Inlier. Several additional species of Ottokaria from across Gondwana do not conform precisely to the diagnosis of that genus and their taxonomic reappraisal is proposed.
KEYWORDS: Xylopteris, Umkomasia, Corystospermaceae, Santa Maria Formation, Middle-Upper Triassic, Brazil, Formación Santa Maria, Triásico Medio y Superior, Brasil
The fossil genus Xylopteris was conceived for Corystospermales fronds presenting pinnate and basally bifurcate pinnae bearing narrow one-veined segments. Later, the possibility was proposed that some of its forms may include 2–3 bifurcated fronds with lobed pinnules and more complex venation. The fossil record attests to its exclusive occurrence in Middle-Upper Triassic Dicroidium floras from Gondwana. Among these, a significant portion of Xylopteris-related morphotypes was included either in the genus Dicroidium or as its subgenus. Such taxonomic placement was adopted in previous studies in Brazil. The new morphotypes herein described present an unsuspected diversity marked by well-preserved frond impressions accompanied by partially preserved Umkomasia strobili. They were identified in a limited exposure of lacustrine shales, at the top of the main fluvial succession of the Passo das Tropas Member, the lower lithostratigraphic unit of the Santa Maria Formation, in the Paraná Basin succession. Given the absence of anatomical structures, the proposed affinity with Xylopteris is based on the original characteristics assigned in the emended diagnosis and in comparisons with other Gondwana records. The described materials attest to the presence of widely distributed types, such as X. elongata, X. spinifolia, X. remotipinnulia and X. rigida as well as X. densifolia, which is restricted to South America and Africa. X. rotundipinnulia, a new generic combination and new species, is proposed for material from Southern Brazil and is comparable to that found in the Molteno beds. The obtained data expands the paleogeographic distribution of the genus and extends the age of the Dicroidium flora in Southern Brazil to the Carnian.
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