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We document for the first time Miocene corals from the Siamaná and Jimol formations of the Cocinetas Basin in La Guajira Peninsula, northern Colombia. This is the first of two contributions dedicated to the description and detailed illustration of morphospecies collected during two scientific expeditions (2011, 2014) to the remote region. Here we report coral morphospecies attributed to the families Acroporidae, Agathiphylliidae, Astrocoeniidae, Caryophylliidae, Diploastraeidae, Merulinidae, and Montastraeidae. Eighteen species belonging to these seven families, included in nine genera, are described. Fifteen species are assigned to established taxa, while three remain in open nomenclature. Of the species identified, only Montastraea cavernosa (Linnaeus, 1767) exists today. The coral taxa described are typical of the Oligocene–Miocene transition and were important components of shallow-water reefs in the Caribbean and Gulf of Mexico region during this period. The occurrence of Agathiphyllia spp., Antiguastrea, and Diploastrea spp. confirms the presence of these genera in the Miocene of the Southern Caribbean. Coral assemblages suggest that the La Guajira coral community thrived in calm and shallow waters.
The new endemic genus Neuquemya, from Pliensbachian deposits in west-central Argentina, is here described and tentatively referred to the Cuspidariidae on account of its shell characters. The new species Neuquemya leanzaorum has a thin, inflated shell, rounded anteriorly and rostrate posteriorly, with a narrow posterodorsal gape and opisthogyrous umbones. The hinge region bears small cardinal tubercles. The shell is ornamented by commarginal (anterior) and radial (posterior) sculpture, whereas the rostrum is smooth. The general and detailed characters of the shell are thus very similar to those of living cuspidariids. Cuspidariids are extremely specialized bivalves with special features related to their carnivorous habit. Their fossil record is scarce, and their phylogeny is poorly understood. Because a few key shell characters and all soft body features of the new genus are unavailable, the alternative possibility that his taxon could be a remarkable example of a homoeomorphic shell cannot be dismissed. If actually a cuspidariid, Neuquemya n. gen. becomes the oldest known member of the family ca. 100 Myr older than the Late Cretaceous records unequivocally accepted and supports the argument that the origin of the group is much older than its known fossil record. The possible relationships of the new genus with other poorly known Mesozoic genera are discussed. Although septibranchs in general and cuspidariids in particular are now conspicuous elements of deep-sea faunas, this new genus inhabited nearshore environments of the Neuquén Basin.
Ascocerid cephalopods are described for the first time from high paleolatitudes of Gondwana. Studied material was collected from the Hirnantian?–Llandovery strata of the Eusebio Ayala and Vargas Peña formations, Paraná Basin, southeastern Paraguay. The specimens are poorly preserved and were questionably assigned to the subfamily Probillingsitinae Flower, 1941, being undetermined at genus and species rank because diagnostic characters are not visible. A particular feature seen in our material is the presence of both parts of the ascocerid conch (the juvenile or cyrtocone and the mature or brevicone) joined together, which is a very rare condition in the known paleontological record. The specimens are interpreted as at a subadult stage of development because fully grown ascocerids would have lost the juvenile shell. A planktonic vertical migrant mode of life with a subvertical attitude is proposed for the juvenile, and a horizontal demersal nektonic mode for the adult form, as has been previously suggested. A subvertical orientation near the bottom is proposed for the subadult stage. We suggest that the immigration of ascocerids to southwestern Gondwana was possible through ocean currents that would carry the planktonic juveniles from low to high latitudes during the end-Ordovician postglacial transgression that flooded the intracratonic basins of the region.
Bed-by-bed sampling of the lower portion of the Daye Formation at Gujiao, Guizhou Province, South China, yielded new Griesbachian–Dienerian (Induan, Early Triassic) ammonoid faunas showing a new regional Induan ammonoid succession. This biostratigraphic scheme includes in chronological order the late Griesbachian Ophiceras medium and Jieshaniceras guizhouense beds, and the middle Dienerian Ambites radiatus bed. The latter is recognized for the first time as a separate biozone in South China. Eight genera and 13 species are identified, including one new species, Mullericeras gujiaoense n. sp. The new data show that a relatively high level of ammonoid taxonomic richness occurred rather rapidly after the Permian/Triassic mass extinction in the late Griesbachian, echoing similar observations in other basins, such as in the Northern Indian Margin.
The Moscow Syneclise on the East European Platform is an important area for the study of the continental biota of late Permian to Early Triassic age in continuous sections. This study attempts a taxonomic description of the late Permian conchostracan fauna of this area. The rich, new material was collected, bed by bed, during geological and paleontological excavations of lacustrine and fluvial deposits of the Obnora Formation and Vokhma Formation of the late Permian Zhukovian Regional Stage near the towns of Vyazniki and Gorokhovets. The conchostracan fauna of the Zhukovian Regional Stage consists predominantly of Pseudestheria and less frequently of Palaeolimnadiopsis. In the earliest Triassic Vokhmian Regional Stage, a more diverse fauna including Euestheria, Magniestheria, Cornia, Palaeolimnadiopsis, and Rossolimnadiopsis was already recorded. The preliminary taxonomic determination of the pseudestheriids from the Zhukovian Regional Stage is intended to serve as a prerequisite for future studies of late Permian conchostracan biostratigraphy on the regional to interregional scale.
A new fossil spider is described from the early Eocene (Ypresian) Palana Formation (54 to 57 Ma) at the Gurha opencast lignite mine, near Bikaner, western Rajasthan, India. It is the first report of a nonamber fossil spider from India. The fossil is referred to the modern genus NephilaLeach, 1815, but with hesitation because, while its habitus is similar to that genus, it lacks the behavioral synapomorphies that distinguish the genus.
Sertulaster keslingi new genus new species (Palaeasteridae) and Delicaster hotchkissi new species (Permasteridae) are asteroid echinoderms described, respectively, from the Ordovician and Carboniferous of eastern North America. The new genus and species help to document diversity within taxa of lower rank. S. keslingi is similar to the Early Ordovician EriasterBlake and Guensburg, 2005 but exhibits less differentiation of the skeletal elements from beyond the ambulacral column, that of the so-called extraxial skeleton, whereas the comparatively robust construction of Delicaster hotchkissi clearly departs from that of the type species, D. enigmaticus (Kesling, 1967). Small sample sizes and incomplete exposure of available specimens illustrate ambiguities typically encountered in the study of fossil asteroids.
Phosphatic sclerites of the problematic TarimspiraYue and Gao, 1992 (Cambrian Series 2) recovered by weak acid maceration of limestones display a unique range of mainly strongly coiled morphologies. They were likely organized into multielement scleritomes, but the nature of these is poorly known; some sclerites may have had a grasping function. Tarimspira sclerites grew by basal accretion in an analogous fashion to younger paraconodonts (Cambrian Series 3–4) but lack a basal cavity. Based on proposed homologies, Tarimspira may provide an extension of the early vertebrate paraconodont–euconodont clade back into the early Cambrian. Tarimspira is described for the first time from Laurentia (North Greenland), extending its known range from China and Siberia in Cambrian Series 2. In addition to the type species, Tarimspira planaYue and Gao, 1992, the Greenland record of Tarimspira includes two morphotypes of a new species, Tarimspira artemi.
The apparatus of Vogelgnathus simplicatus (Rhodes, Austin, and Druce, 1969) is reconstructed from discrete elements from a sample of limited diversity from the Limerick Province (Ireland). The apparatus is typical of the order Ozarkodinida and the P1 element was previously placed within Gnathodus. Here we assign it to Vogelgnathus by applying a multielemental concept rather than using P1 element morphology. The holotype and paratypes are re-illustrated and the species distribution revised based on published data. Vogelgnathus simplicatus ranges from the late Tournaisian to the early Viséan (Mississippian, Carboniferous), with common occurrences relating to the growth of Waulsortian bank complexes in a high-stand sea-level along the southern and western margins of the Laurussian landmass (Belgium, the British Isles, the Republic of Ireland, and USA). Vogelgnathus simplicatus appears to represent the rootstock from which deep-water and shallow-water Viséan species of Vogelgnathus evolved in the Mississippian.
Dissorophoid temnospondyls are widely considered to have given rise to some or all modern amphibians (Lissamphibia), but their ingroup relationships still bear major unresolved questions. An inclusive phylogenetic analysis of dissorophoids gives new insights into the large-scale topology of relationships. Based on a TNT 1.5 analysis (33 taxa, 108 characters), the enigmatic taxon Perryella is found to nest just outside Dissorophoidea (phylogenetic defintion), but shares a range of synapomorphies with this clade. The dissorophoids proper are found to encompass a first dichotomy between the largely paedomorphic Micromelerpetidae and all other taxa (Xerodromes). Within the latter, there is a basal dichotomy between the large, heavily ossified Olsoniformes (Dissorophidae + Trematopidae) and the small salamander-like Amphibamiformes (new taxon), which include four clades: (1) Micropholidae (Tersomius, Pasawioops, Micropholis); (2) Amphibamidae sensu stricto (Doleserpeton, Amphibamus); (3) Branchiosauridae (Branchiosaurus, Apateon, Leptorophus, Schoenfelderpeton); and (4) Lissamphibia. The genera Platyrhinops and Eoscopus are here found to nest at the base of Amphibamiformes. Represented by their basal-most stem-taxa (Triadobatrachus, Karaurus, Eocaecilia), lissamphibians nest with Gerobatrachus rather than Amphibamidae, as repeatedly found by former analyses.
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.
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 gorafensisRuiz Bustos et al., 1984; A. gudrunaevan de Weerd, 1976; A. dominansKretzoi, 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. eliomyoidesKretzoi, 1959), an eomyid (Keramidomys aff. K. ermannorumDaxner-Höck and Höck, 2009), two ochotonids (Prolagus sorbiniiMasini, 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 (PseudomerionesSchaub, 1934; OchotonomaSen, 1998) indicate Asiatic affinities.