A rich echinoid fauna within the middle Miocene carbonate sedimentary succession cropping out along the coast between Santa Caterina di Pittinuri and S'Archittu (central-western Sardinia) allows the comparison of faunal gradients and preservation potentials from both hard and soft substrata. Three echinoid assemblages are recognized. Faunal composition, as well as taphonomic and sedimentological features and functional morphological interpretation of the echinoid test indicate an outer sublittoral setting. Assemblage 1 represents a highly structured environment within the photic zone, with mobile substrata occupied by infaunal irregular echinoids, mainly spatangoids, and localized hard substrata, provided by rhodolith beds, with epibenthic regular echinoids represented by the co-occurrence of the diadematid Diadema Gray, 1825 and the toxopneustids Tripneustes L. Agassiz, 1841 and Schizechinus Pomel, 1869. Assemblage 2 shows a higher diversity of irregular echinoids, dominated by the clypeasteroids Echinocyamus van Phelsum, 1774 and Clypeaster Lamarck, 1801 and different spatangoids, with the minute trigonocidarid Genocidaris A. Agassiz, 1869 among regular echinoids. This assemblage points to a soft-bottom environment with moderate water-energy conditions, periodically affected by storms. A low-diversity echinoid fauna in Assemblage 3, dominated by the spatangoids Brissopsis L. Agassiz, 1840 and Ova Gray, 1825, documents a deeper, soft-bottom environment, possibly below storm-wave base. These results indicate that the diversity of echinoid faunas originating in sublittoral environments is related to: (1) the presence of both soft and hard substrata, (2) differential preservation potentials of the various echinoid taxa, (3) intense bioturbation, and (4) sediment deposition by sporadic storm events.

The giant carnivorous phorusrhacid bird Phorusrhacos longissimus (Aves, Cariamiformes) was first described in 1887 by Florentino Ameghino on the basis of a jaw fragment. The majority of a skull of the species still encased in crumbling rock was preserved only long enough for illustrations to be made by Carlos Ameghino in the field and for a brief description to be written. Skull remains of this species have remained scarce, and few postcranial remains have been figured. Here, we reassess the cranial anatomy of this outstanding ‘terror bird’ species taking into account data from a newly discovered skull. An additional specimen of a well-preserved dorsal vertebra referable to Phorusrhacinae is also described from a separate locality within the Miocene Santa Cruz Formation (late early Miocene) from Santa Cruz Province in Argentina. The skull includes most of the rostrum, skull roof, and mandible and is compared with material from other members of the Phorusrhacinae. The new data from the skull and vertebra provide morphological features of this clade that benefit future taxonomic and phylogenetic analyses of this iconic group of birds.

We revisit the holotype of Calcardea junnei Gingerich, 1987 from the latest Paleocene (Clarkforkian) of the Willwood Formation (Wyoming, USA). The species is based on a partial skeleton and was originally assigned to the Ardeidae (herons). As we show, this classification cannot be upheld and Calcardea Gingerich, 1987 more closely resembles the taxon Vastanavis Mayr et al., 2007 (Vastanavidae), a parrot-like bird from the early Eocene of India. Even though C. junnei is a large bird, its long wings and short tarsometatarsus argue against a predominantly terrestrial way of living, and the morphology of the tarsometatarsus and pedal phalanges instead suggest strong grasping feet. We conclude that an assignment of Calcardea to the landbird clade (Telluraves) is better supported than its classification into the waterbird clade (Aequornithes), which includes Ardeidae and other ‘ciconiiform’ and ‘pelecaniform’ taxa. Calcardea junnei is one of the oldest known representatives of Telluraves and its morphology shows plesiomorphic features, which contributed to its previous misidentification as a heron. Calcardea exhibits a distinctive osteology and affords a glimpse of a previously unknown late Paleocene avian morphotype.

A new specimen of a theropod dinosaur found in the Upper Jurassic (Freixial Formation, late Tithonian) of the Lusitanian Basin is described. It corresponds to a single individual and includes a sequence of articulated caudal vertebrae, an almost complete right pes, and other fragments of the appendicular skeleton. The specimen includes the most complete pes of a theropod dinosaur currently known in the Lusitanian Basin and represents one of the youngest skeletal records of theropod dinosaurs currently known in the Portuguese Upper Jurassic.

A systematic analysis of this specimen is performed and it shows a combination of characters that allows us to interpret it as belonging to an allosauroid taxon. Within this clade, the material from Cambelas shares a few features with some carcharodontosaurids, including the presence of a lateral lamina extending along the anterior end of the centrum in the caudal vertebra and of a low vertical crest on the lateral surface of the femoral lesser trochanter. The set of remains described here shares some unusual features with another specimen previously described in the Portuguese fossil record, which also presents some synapomorphies of Carcharodontosauria. However, no autapomorphy or exclusive character combination can be recognized in the specimen here described in order to describe it as a new form. The presence of this specimen suggests a greater diversity in the allosauroid theropod fauna from the Late Jurassic of the Lusitanian Basin than currently known and probably expands the temporal record of Carcharodontosauria up to upper Tithonian of south-western Europe.

The recent 2014–2017 controlled excavations carried out in quarries of Sverdlovsk and Tyumen regions, Ural and Western Siberia, are contributing to the knowledge of the middle to late Eocene marine fauna from the Turgay Strait, mainly composed of invertebrates and cartilaginous and bony fishes. Here we present a preliminary report of the bony fishes collected during the campaigns carried out in two Eocene Trans-Urals localities. The sediments of these localities were deposited in a large epicontinental marine basin during the middle to late Eocene, when the Turgay Strait connected the Arctic waters to the North and the Peritethys to the South. Most of the bony fish material examined can be assigned to codfishes (Gadiformes) according to morphological comparison with living and fossil taxa. In particular, nearly complete three-dimensionally preserved lower jaws are confidently assigned to the Merlucciidae, whereas isolated vertebrae and bones are referred to as Gadiformes incertae sedis. This report documents the easternmost occurrence of this group of fishes in the northern hemisphere during the early phases of their radiation, revealing their presence into the Turgay Strait before its closure.

New fossil material of Auliscomys formosus Reig 1978 allows restudy of the oldest known South American representative of the subfamily Sigmodontinae. Description of Auliscomys formosus was based on a fragmentary dentary exhumed from the Monte Hermoso Formation of central Argentina. Previous studies allocated A. formosus to the early Pliocene. A reevaluation of dental and cranial morphology, including for the first time the upper dentition, and the inclusion of A. formosus in a phylogenetic analysis of the tribe Phyllotini indicate that A. formosus represents a new genus, Kraglievichimys. Kraglievichimys shares a mosaic of characters with the living Auliscomys Osgood, 1915 and Loxodontomys Osgood, 1947. The taxonomic reassignment of A. formosus and the possibility that the Monte Hermoso Formation may be younger than early Pliocene in age provide a new understanding of cricetid diversification in South America. Estimates of sigmodontine ancestry by molecular approaches are biased toward older ages, whereas this new interpretation of the history of K. formosus suggests that the South American history of sigmodontines spans less than 4 million years.

UUID: http://zoobank.org/49dd8f60-56b1-4e8a-a044-6cea3a1bd52b

Beremendiini is an extinct group of soricine shrews that were widely distributed during the Pliocene and Pleistocene. Their occurrence in China has been investigated, but their presence in northern Asian regions has remained poorly studied. This paper analyzes 56 fossil remains of Beremendiini collected from 16 early Pliocene to early Pleistocene localities in Russia (Siberia), Kazakhstan, and Mongolia and shows the presence of two beremendiin species: Beremendia fissidens (Petényi, 1864) and Beremendia minor Rzebik-Kowalska, 1976. Northern Asian Beremendia considerably vary in size and qualitative characteristics, although most of the different states have been identified in European or Chinese specimens. Through the application of geometric morphometric techniques, mandibular shape analyses reveal similarities between the members of the beremendiin genera Peisorex Kowalski and Li, 1963, Beremendia Kormos, 1934, and Lunanosorex Jin and Kawamura, 1996. Shape analyses and comparisons of mandibular characteristics reveal ‘trophic’ analogies between Beremendia and Blarina spp. and a new model of ‘Mandible Swinging and Sliding’ (MSS-model) accounting for the similarities in mandibular morphology with implications for the understanding of the diet of Beremendia.

UUID: http://zoobank.org/ef92ee1a-3977-44b2-86d7-381665bcf78b

Three localities in the Çankırı Basin—Kale Tepe 1 (KT1), Kale Tepe 2 (KT2), and Mahmutlar—yielded reliably documented rodent and lagomorph assemblages. These are in the Akkaşdağı Formation, which covers large areas in the central and southern parts of this basin in Central Anatolia. The widening of the Kirikkale-Çorum highway produced fresh outcrops that allowed for the discovery of fossiliferous levels in a well-controlled stratigraphy. The assemblages from all three localities are dominated by muroid rodents (Apodemus gorafensis Ruiz Bustos et al., 1984; A. gudrunae van de Weerd, 1976; A. dominans Kretzoi, 1959; Micromys sp. indet.; Allocricetus sp. indet.; Pseudomeriones sp. indet.; Cricetidae gen. indet. sp. indet.; Mimomys sp. indet.) in addition to a glirid (Dryomimus cf. D. eliomyoides Kretzoi, 1959), an eomyid (Keramidomys aff. K. ermannorum Daxner-Höck and Höck, 2009), two ochotonids (Prolagus sorbinii Masini, 1989; Ochotonoma sp. indet.) and one leporid. KT1 and KT2 yielded two large species of Apodemus (A. gorafensis; A. gudrunae) that are typical for the late Miocene/early Pliocene transition in southern Europe, and they are known in Greece and Turkey in localities dated to the latest Miocene, i.e., MN 13 mammalian zone. The occurrence of A. dominans and a rooted arvicolid similar to Mimomys davakosi van de Weerd, 1979 suggests correlation of Mahmutlar to the early Pliocene, or early MN 15 zone. An abundance of muroid rodents in these assemblages indicates woodlands and areas covered by grasses and shrubs, whereas early Pliocene deposits at Mahmutlar provided pollen of abundant herbaceous and shrub elements. Most rodents and lagomorphs from Kale Tepe and Mahmutlar are known in southern European bioprovinces, whereas some elements (Pseudomeriones Schaub, 1934; Ochotonoma Sen, 1998) indicate Asiatic affinities.

The Neognathodus Index (NI) is developed as a primary biostratigraphic indicator for the Desmoinesian Series of the Illinois Basin in Indiana, Illinois, and Kentucky. It is based on the gradual evolutionary morphotypic variations of P1 elements of named species of Neognathodus Dunn, 1970. The NI analyses and zonations presented herein are constructed from 472 productive conodont samples from 105 different localities. NIs for the Illinois Basin show morphologic drift in Indiana from the Perth Limestone Member of the Staunton Formation (NI = 2.03) to the Velpen Limestone and Mecca Quarry Shale members of the Linton Formation (NI = 5.04) followed by stability through the Alum Cave (NI = 4.83). Further morphologic drift then occurred through the Providence Limestone Member of the Dugger Formation (NI = 5.43) and continued through the West Franklin Limestone Member of the Shelburn Formation (NI = 6.32) until the extinction of Neognathodus at the end of Desmoinesian. The patterns of drift and stability translate to Neognathodus biozones and are supported by Kolmogorov-Smirnov tests of standardized Neognathodus morphotype distributions. Localized NI variations are due to morphologic shifts and differential evolution in response to localized environmental conditions. Examination of the NI differences in the states of Illinois, Kentucky, and Indiana reflect similar morphologic simplification of the P1 element from Perth to Velpen and Mecca Quarry in Indiana (NI = 2.03–5.04) and from Seville to Brereton in Illinois and Kentucky (NI = 2.80–5.00). Post-Brereton in Illinois and Kentucky (NI = 5.00–5.65) and post-Providence in Indiana (NI = 5.43–6.32) saw progressive P1 simplification, but it was much more pronounced in Indiana.

Large body sizes among nonavian theropod dinosaurs is a major feature in the evolution of this clade, with theropods reaching greater sizes than any other terrestrial carnivores. However, the early evolution of large body sizes among theropods is obscured by an incomplete fossil record, with the largest Triassic theropods represented by only a few individuals of uncertain ontogenetic stage. Here I describe two neotheropod specimens from the Upper Triassic Bull Canyon Formation of New Mexico and place them in a broader comparative context of early theropod anatomy. These specimens possess morphologies indicative of ontogenetic immaturity (e.g., absence of femoral bone scars, lack of co-ossification between the astragalus and calcaneum), and phylogenetic analyses recover these specimens as early-diverging neotheropods in a polytomy with other early neotheropods at the base of the clade. Ancestral state reconstruction for body size suggests that the ancestral theropod condition was small (~240 mm femur length), but the ancestral neotheropod was larger (~300–340 mm femur length), with coelophysoids experiencing secondary body size reduction, although this is highly dependent on the phylogenetic position of a few key taxa. Theropods evolved large body sizes before the Triassic–Jurassic extinction, as hypothesized in most other ancestral state reconstructions of theropod body sizes, but remained rare relative to smaller theropods until the Jurassic.

Living Caprini are dominant bovids in the pan-Tibetan area that are strongly adapted to dry steppe and high-mountain meadow habitats. Some taxa with Holarctic distributions, e.g., Ovis Linnaeus, 1758, were thought to originate on the Tibetan Plateau and subsequently dispersed elsewhere, which was depicted as an ‘out of Tibet’ story. However, except for some information on a stem caprine assemblage from the Qaidam Basin, the early evolution of Caprini around the Tibetan Plateau is poorly known. Here, we report new material of Olonbulukia tsaidamensis Bohlin, 1937, which was a member of this stem caprine assemblage, from the Wuzhong region, northern China, confirming the similarity of the Wuzhong Fauna and ‘Qaidam Fauna.’ Based on a biometric study of horncores from the ‘Qaidam’ and Wuzhong faunas, we recognize six taxa from this stem caprine assemblage: O. tsaidamensis, O. sp., Qurliqnoria cheni Bohlin, 1937, Tossunnoria pseudibex Bohlin, 1937, ?Protoryx cf. P. enanus Köhler, 1987, and cf. Pachytragus sp. Among these taxa, Q. cheni and T. pseudibex are probably related to some extant Tibetan endemic species, e.g., the Tibetan antelope, Pantholops hodgsonii (Abel, 1826), and the Himalayan tahr, Hemitragus jemlahicus (Smith, 1826). Others might be ancestral to the Turolian caprine assemblages and even possibly gave rise to the extant Caprina. This work reveals an early radiation of stem caprines along the northern side of the rising Tibetan Plateau and indicates a mixed pattern of pan-Tibetan stem caprine evolution prior to their dispersal out of the Tibetan Plateau.

Xenarthra is an endemic South American lineage of mammals, probably the sister clade of the other placental mammals. The oldest records of Xenarthra are from the latest Paleocene, although its current diversity is much lower than that recorded in some intervals of the Cenozoic Era. A new Neogene Xenarthra (Pilosa and Cingulata) assemblage from two localities of the Argentine Eastern Puna (Calahoyo and Casira) is described. The newly recorded taxa—Cingulata, Dasypodidae, Eutatini: Stenotatus sp. indet. and Eutatini indet., Euphractini: Macrochorobates scalabrinii (Moreno and Mercerat, 1891), and Tardigrada, Mylodontinae: cf. Simomylodon sp. indet. and Simomylodon cf. S. uccasamamensis Saint-André et al., 2010—and those already published from Calahoyo—Cingulata: Macrochorobates chapadmalensis (Ameghino, 1908), Eosclerocalyptus sp. indet., and Tardigrada, Megatheriidae: Pyramiodontherium bergi (Moreno and Mercerat, 1891)—suggest a middle–late Miocene age for the fossil-bearing levels. In Calahoyo, the presence of Stenotatus sp. indet., in addition to some rodents currently under study in the lower levels, suggest a closer similarity with the palaeofauna of Cerdas (southern Bolivia), probably involving the last part of the Miocene Climatic Optimum. The Xenarthra recorded in the middle and upper levels of Calahoyo and Casira suggest a late Miocene–Pliocene age. A comparative analysis between Calahoyo and Casira highlights the absence of Cingulata in the latter and a high diversity in the former. This situation probably indicates different paleoenvironmental conditions. Finally, we present the first certain record of the genus Simomylodon Saint-André et al., 2010 in Argentina, which includes the oldest record of dermal ossicles for sloths in South America.

Peligrochelys walshae is a meiolaniform turtle originally described based on four specimens represented by cranial remains found in the classic locality of Punta Peligro (Chubut, Argentina) in outcrops of the Salamanca Formation (Danian). Recent field work in the vicinity of Punta Peligro resulted in the discovery of almost 30 new specimens, represented by cranial and postcranial remains that can be assigned to P. walshae. In this contribution, we provide a detailed anatomical description of the new specimens, provide an emended diagnosis for the species, and explore its phylogenetic relationships based on all anatomical data available for the species. The new specimens bring valuable information about the anatomy of the skull and postcranium of P. walshae as well as for meiolaniforms in general. The 3D preservation of the skull bones allows us to provide a 3D reconstruction using novel techniques. The updated phylogenetic analysis confirms that P. walshae is part of the clade Meiolaniformes, which spans from the Early Cretaceous until the Holocene and contains the giant, horned turtles (Meiolaniidae). This phylogenetic analysis reinforces the previous hypothesis that the clade Meiolaniformes is dominated by Gondwanan taxa, but also includes some Laurasian representatives. Alternate phylogenetic positions of taxa included in Meiolaniformes in this analysis were tested using the Templeton test. The lineage leading to Peligrochelys walshae is the only meiolaniform non-meiolaniid lineage to have survived the K-Pg mass extinction; its study provides valuable information to evaluate the effects of the K-Pg extinction in turtles.

Barrande erected the genus Aristocystites, type A. bohemicus Barrande, in 1887. He listed other questionable species, including “A.? subcylindricus var. de bohemicus.” Aristocystites subcylindricus has not been accepted apart from Bather who in 1919 designated a type specimen and made it the type species of the new genus Hippocystis. No specimens available to Barrande or Bather preserved the oral area necessary to characterize Hippocystis or A. subcylindricus. Specimen 436969A, in the United States National Museum of Natural History is a more complete specimen of A. subcylindricus and preserves the oral area. This shows that A. subcylindricus is a valid species, but has two ambulacral facets, a character unique to the genus Aristocystites. Aristocystites subcylindricus has tumid plates with obvious sutures, a rounded thecal base, and a gonopore surrounded by three plates. Aristocystites bohemicus has smooth plates, an obvious attachment scar aborally and a gonopore within a single plate. Both species have occasional horseshoe-shaped diplopores.

UUID: http://zoobank.org/946c28a2-5783-4a6b-9111-416857bf9363

Tang et al. (2019) described new specimens of carbonaceous compression fossils from the early Cambrian Hetang Formation in South China, for which they established the new taxon Cambrowania ovata Tang and Xiao in Tang et al., 2019. Tang et al. (2019) interpreted these fossils as the remains of metazoans, representing either the carapaces of bivalve arthropods, or early life-cycle stages of sponges. We contest the animal affinity of these fossils; instead, we propose that the specimens described as Cambrowania ovata are actually large Leiosphaeridia—in other words, collapsed hollow organic spheroidal acritarchs. The features described by Tang et al. (2019) all fall into the morphology of carbonaceous compressions of Leiosphaeridia with pyritized/baritized folds and compaction wrinkles. Such Leiosphaeridia are a common component of Cambrian (and older) siliciclastic deposits, and frequently exhibit such a pattern of pyritization, baritization, and encrustation with other diagenetic minerals.