Here we describe a new notoungulate mammal from the early Eocene (Itaboraian SALMA) of Chubut, Argentinian Patagonia, from the localities of Las Flores and Las Violetas Farm, represented by fragments of maxilla and isolated teeth. The specimens were found in the Las Flores Formation, Ro Chico Group, and assigned to the Henricosborniidae, a primitive family within the order Notoungulata. Orome deepi gen. et. sp. nov. differs from other henricosborniids in a less developed metacone column in the upper molars, a larger metaloph in the third upper molar and a larger mean size. The morphometric analysis does not show any difference between the individuals of the two studied localities. The new addition to the henricosborniid diversity in Patagonia allows to provide a better understanding of the early radiation of notoungulates in South America.

Polyphysacean algal fertile caps from the Sarmatian near Suceava (NE Romania) are here described as a new species, Acetabularia moldavica, ascribed to the extant genus Acetabularia due to the presence of both inferior and superior coronae. Gametangia are preserved and closely packed within the gametophore. The gametangium wall is strongly mineralized and SEM observations show acicular aragonite crystals arranged perpendicularly to the wall surface. The occurrence of mineralized cyst walls distinguishes the new species from the other three species ascribed to the genus Acetabularia, namely Acetabularia miocaenica, Acetabularia chiavonica, and Acetabularia transylvana. Cyst wall biomineralization in A. moldavica sp. nov., Chalmasia, and Halicoryne appears to assist in distinguishing taxa at species level but not at genus level. Four types of intracellular biomineralization can be recognized in polyphysaceans according to the mineralization of cyst walls and intergametangial spaces. The attribution of an extant species to a fossil genus and vice-versa can be problematic when the fossil consists of a mineralized spicule (intracellular biomineralization). Two contrasting examples are Acetabularia schenckii (extant species) assigned to the genus Acicularia (fossil), and Halicoryne morelleti (fossil species) referred to an extant genus (Halicoryne). When it is unclear whether fossil taxa possessed one or two coronae, the attribution of Cenozoic species to an extant genus appears speculative. Therefore, we support the view that the genus Acicularia should only be applied to fossil species. In addition, mineralized aggregates of cysts of Halicoryne morelleti should be distinguished from their possible extant counterparts (Chalmasia, Halicoryne, and Acetabularia ) when coronal structures are not preserved. In the literature Halicoryne morelleti has been compared with the fossil genera Sedalanella and Ioanella. The first genus must be considered a junior synonym of Oroseina. A new interpretation of the genus Ioanella is supplied. The two layers of cysts of Ioanella conform poorly with the small ellipsoidal calcareous bodies of Halicoryne morelleti. Therefore, we propose the new genus Patruliuspora for Halicoryne morelleti.

Fossil turtles are one of the least studied clades in regard to endocranial anatomy. Recently, the use of non-invasive technologies, such as radiographic computed tomography (CT), increased the knowledge of the neuroanatomy of several extinct and extant taxa. Here, we provide the description of the nasal cavity, cranial endocast, and inner ear of the stem turtle Naomichelys speciosa based on digital 3D reconstructions. This terrestrial form is characterized by a nasal cavity with anteroposteriorly elongated vestibulum and a large cavum nasi proprium, traits typically related to terrestrial habits. The large olfactory region of the cavum nasi proprium suggests that olfaction was probably the most important sense for this species. Our description of N. speciosa adds novel information to the knowledge of endocranial anatomy in early turtle evolution and provides an important foundation for future analyses and comparisons.

Spermophilus is the most diverse and abundant genus of Eurasian sciurids. Even though many species have been described, the early evolution of the group is poorly understood. Here we present a review of the evolution and taxonomy of early Spermophilus, based on analysis of more than 1500 specimens from the late Pliocene and Early–Middle Pleistocene of Ukraine and European Russia, representing the most complete and continuous fossil record of the early Old World ground squirrels known to date. In addition to documenting previously unpublished specimens of Spermophilus nogaici, we describe a new species, Spermophilus praecox sp. nov., the oldest member of the genus, from the late Pliocene and Early Pleistocene (middle Villanyian to earliest Biharian) of southern Ukraine. It is intermediate in size between a somewhat smaller Spermophilus nogaici and larger Spermophilus polonicus and Spermophilus primigenius. Morphologically, the new species can be distinguished from all known Spermophilus by the retention of primitive traits including a small P3; rudimentary lingual metaloph; large metaconule and mesostyle; presence of P4–M2 endoloph; and premolariform p4 lacking a lingual metalophid. The patterns of dental evolution in eastern European early Spermophilus throughout 2.15 My indicates the existence of a single gradually evolving S. praecox–S. nogaici lineage characterized by a decrease of molar size but enlargement of premolars; the tendency toward high-crowned teeth with more expanded anterior and reduced posterior lobes; well-developed transverse ridges and anterostyles; reduced endolophs, anteroconules, metaconules, and mesostyles of P4–M2; molariform p4; complete m1–m2 metalophids; and stronger m3 hypoconid, hypoconulid, and entoconulid. Dental character regression suggests that Spermophilus evolved from a relatively large-sized sciurid having generalized Otospermophilus-like dentition, probably an unknown North American member of stem Marmotina. Copyright © 2019 M.V. Sinitsa and N.V. Pogodina. This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Chambi-Trowell, Sofia A.V., Whiteside, David I., Benton, Michael J. (2019): Diversity in rhynchocephalian Clevosaurus skulls based on CT reconstruction of two Late Triassic species from Great Britain. Acta Palaeontologica Polonica 64 (1): 41-64, DOI: 10.4202/app.00569.2018, URL: http://dx.doi.org/10.4202/app.00569.2018

Here we describe a new species of the metriorhynchid thalattosuchian Cricosaurus, C. bambergensis sp. nov., from the Upper Jurassic Torleite Formation of Wattendorf near Bamberg, Bavaria (southern Germany). The holotype and only known specimen is a nearly complete skeleton that shows a number of diagnostic traits including a bicarinate dentition formed by labiolingually compressed tooth crowns that lack a conspicuous enamel ornamentation and the presence of a distinct midline ridge with paired depressions on the palatines. Our phylogenetic analysis recovers a grouping of Cricosaurus bambergensis sp. nov. with C. elegans and C. suevicus. The implications of the new Cricosaurus species to the species complex from the late Kimmeridgian–early Tithonian of southern Germany is discussed. Our description of C. bambergensis demonstrates that the specific, and morphological, diversity of Cricosaurus in southern Germany was higher than previously thought. This coincides with the recent trend of re-evaluating the species-complexes of extant taxa, and the identification of new “cryptic species”. As such, the crocodylomorph fossil record will need to be re- examined to ensure there is not an underestimation of their biodiversity.

Megaraptora is a clade of mid to large-sized theropods that are long-snouted, large-clawed, highly pneumatized, and have long and gracile metatarsals. The basal member was reported from the Barremian of Japan. A more derived clade, the Megaraptoridae, is known from the Cenomanian to Santonian of Gondwana. Here two new basal coelurosaurs from the Lower Cretaceous Sao Khua Formation of Thailand are described and named as Phuwiangvenator yaemniyomi gen. et sp. nov. and Vayuraptor nongbualamphuensis gen. et sp. nov. Phuwiangvenator is a megaraptoran coelurosaur and diagnosed by the ventrally flat sacral vertebrae with sulci in the anterior and posterior region of the centra and the anterior rim of metatarsal IV sloping proximolaterally to distomedially and being much lower than that of metatarsal III anteriorly. Vayuraptor is a basal coelurosaur and diagnosed by its astragalus which has two horizontal grooves, two fossae at the base of the ascending process, the ascending process being straight laterally and straight and parallel medially with the medial rim sloping to the tip laterally, and a long and slender astragalar ascending process. Although the position of the basal coelurosaur Vayuraptor remains unclear and must await further discovery, megaraptoran affinities are likely. The Early Cretaceous megaraptoran fossil record has been recovered from the Barremian to Aptian of Asia. All Asian megaraptorans might be a monophyletic clade or a paraphyletic series relative to the Megaraptoridae. Several specimens have been reported from the Aptian to mid-Cretaceous of Australia, and one report from the Albian of South America. These fossils show a high diversity of the Early Cretaceous megaraptorans and a wide distribution during that time. The clade then became more provincial in the Late Cretaceous.

Fil: Bodnar, Josefina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Area Paleobotanica; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

Despite the exceptional palaeontological richness of the renowned Santana Group from the Early Cretaceous Araripe Basin of Brazil, only one specimen of true crabs (Brachyura) has been discovered to date. Here we present two new genera and species of brachyuran crabs from the upper Aptian-lower Albian Romualdo Formation of the Santana Group, represented by 30 specimens from several localities across the Araripe Basin in the state of Pernambuco, Brazil. One taxon, Exucarcinus gonzagai Prado and Luque gen. et sp. nov., is similar to several endemic stem raninoidans (Orithopsidae) from the late Aptian and early Albian of Colombia and the USA, respectively, while Romualdocarcinus salesi Prado and Luque gen. et sp. nov., seems to be closer to "higher" true crabs (Eubrachyura) from the Cenomanian of Spain. The presence of taxa similar to those from the mid-Cretaceous of northern South America, southern North America, and western Europe, reinforces the view of a Tethyan marine influence in Araripe during the breakup of South America and Africa, and adds to the growing data that suggest a generic and specific degree of endemism of true crabs in tropical South America during the mid-Cretaceous.

Quail-thrushes (Passeriformes: Cinclosomatidae: Cinclosoma) are ground-dwelling corvoid songbirds endemic to Australia and New Guinea. Until now, the only known quail-thrush fossils have been from late Quaternary cave deposits in Australia. A new species of quail-thrush, Cinclosoma elachum sp. nov., is described from the early to middle Miocene deposits in the Riversleigh World Heritage Area, Queensland, Australia. A second, larger quail-thrush is identified from the middle Miocene of Riversleigh. The new fossils considerably extend the geographic and temporal ranges of cinclosomatids, and indicate the presence of two species of quail-thrushes in the Miocene of northern Australia, located more than 300 km from the nearest extant member of Cinclosoma. These fossils provide a minimum age of ~18 million years for Cinclosomatidae. They cannot be confidently assigned to the crown group of the genus Cinclosoma, but can be used to calibrate the split between this genus and Ptilorrhoa in molecular dating studies of the Corvides radiation and Passeriformes overall. This material also adds to the growing diversity of songbirds identified from the pre-Pleistocene record of Australia, and reemphasises the global significance of the Riversleigh deposits in developing understanding about the early evolutionary history of passerines.