Letteratura scientifica selezionata sul tema "Bothremydidae"

Bothremydidae is a successful lineage of pleurodiran turtles that lived from the Cretaceous to the Paleogene, and are found in most continents of both Laurasia and Gondwana. Despite numerous known cranial remains of this clade, no study on the complete neuroanatomical reconstruction of any of its representatives has been published so far. Tartaruscola teodorii is a French lower Eocene member of Foxemydina (Bothremydini), known by two skulls. It is one of the few bothremydids identified in the Cenozoic record of Europe. The present study includes the complete three-dimensional reconstruction of each of the cranial bones of both the holotype and the paratype of T. teodorii, increasing the anatomical information about this species. The virtual reconstruction of its neuroanatomical structures is presented here, including the cranial cavity, nerves, nasal cavity, inner ears, and carotid arteries. This analysis is the first detailed neuroanatomical study performed for a member of Bothremydidae. In addition, the virtual reconstruction of the neuroanatomical structures of some extant taxa belonging to several pleurodiran lineages (Chelidae, Pelomedusidae and Podocnemididae), are also carried out and analyzed, so that the comparative framework for Pleurodira is remarkably improved.

A new pleurodiran turtle is described here. It is identified as attributable to Bothremydidae. The new taxon comes from an upper Maastrichtian (Upper Cretaceous) outcrop located in Southwestern Niger (in the Indamane Mount area, belonging to the Abalak Department of the Tahoua Region). Abalakemys chapmanae gen. et sp. nov. is identified by an almost complete large shell of about 65 cm in length. The new bothremydid turtle is recognized as a member of Bothremydodda, showing several autapomorphies (an exclusive ornamental pattern on the plate’s outer surface, covered by small depressions; small fourth pleural scutes, only anteromedially reaching the sixth pair of costal plates; and noticeably wedged posterior plastral lobe toward the posterior region), as well as a unique combination of characters for this clade. This turtle could belong to Nigeremydini, a poorly understood Maastrichtian to Paleocene lineage of Bothremydodda, which integrates large coastal taxa that inhabited the African Trans-Saharan seaway, and for which shell information is currently extremely limited.

Abstract The continental tetrapod assemblages from the Santonian-Maastrichtian of Europe consist of dinosaurs (theropods: Abelisauroidea, Alvarezsauridae, Dromaeosauridae, ?Oviraptorosauria, ?Troodontidae, and birds: Enantiornithes, basal Ornithurae; sauropods: Titanosauria; ankylosaurs: Nodosauridae; ornithopods: Hadrosauridae, Rhabdodontidae; and neoceratopsians), pterosaurs (Azhdarchidae), crocodyliforms (eusuchians: Alligatoroidea, Gavialoidea, ?Hylaeochampsidae; sebecosuchian-like ziphosuchians; and, probably, basal neosuchians), choristoderes (?Champsosauridae), squamates (lacertilians: Iguanidae s.l., Paramacellodidae, Polyglyphanodontinae, Varanoidea; snakes: Madtsoiidae; possible amphisbaenians), turtles (cryptodires: Chelydroidea, Kallokibotionidae, Solemydidae; pleurodires: Bothremydidae, Dortokidae), lissamphibians (Albanerpetontidae; anurans: Discoglossidae, Palaeobatrachidae; caudates: Batrachosauroididae, Salamandridae), and mammals (multituberculates: Kogaionidae, ?“Paracimexomys group”; marsupials: Herpetotheriidae; eutherians: “Zhelestidae”). The palaeobiogeographical affinities of the Late Cretaceous continental tetrapods of Europe are complex. The faunas are commonly considered to show a mixed pattern resulting from the addition of “Asiamerican” and Gondwanan forms to European taxa. Albanerpetontids, both paramacellodid and polyglyphonodontine lizards, and hadrosaurid dinosaurs are taxa with Palaeolaurasian (or, in some case, even Neopangean) affinities. Other forms, such as paleobatrachid and batrachosauroidid lissamphibians, solemydid turtles, alligatoroid crocodyliforms, and nodosaurid dinosaurs can be considered as Euramerican taxa. Kallokibotionid and dortokid turtles, rhabdodontid dinosaurs and kogaionid mammals are endemic to Europe. The Gondwanan taxa have been regarded as African immigrants that reached southern Europe via the Mediterranean Tethyan sill. Abelisaurid and titanosaurid dinosaurs, trematochampsid crocodyliforms, podocnemidid and bothremydid turtles, and boid and madtsoiid snakes constitute the basic pattern of the so-called “Eurogondwanan fauna”. However, the validity of some of these taxa is a disputed matter (Titanosauridae, Trematochampsidae), and the presence of other taxa in the Late Cretaceous of Europe is based on controversial data (Boidae, Podocnemididae). Only Abelisauroidea, Madtsoiidae and Bothremydidae (and, yet for confirming, Sebecosuchia) provide evidence of interchanges between Africa and Europe. At least abelisauroids might have reached Europe before the Late Cretaceous. In conclusion, most of the continental tetrapod taxa from the latest Cretaceous of Europe show affinities with those of northern Hemisphere landmasses. Latest Cretaceous trans-Tethyan dispersal events between Africa and Europe remain poorly documented.

Abstract. Algorachelus peregrinus is the oldest representative of the crown group Pleurodira known in Laurasia. The type locality of this bothremydid is Algora, situated in central Spain, at levels deposited during the uppermost middle–lowermost upper Cenomanian. A new excavation was recently carried out in this town. As a result, abundant material of Algorachelus peregrinus has been found. Several complete shells, as well as numerous partial carapaces and plastra, are presented here. The abundance of remains allows the analysis of the general patterns by which some of the shells of this littoral form were partially or totally disarticulated. The analysis of these remains not only shows several pathologies but also improves the knowledge about the anatomy and intraspecific variability of Algorachelus peregrinus. This new information allows the revision of other Cenomanian forms of Bothremydidae, both from the Middle East and from North America. Thus, Algorachelus is identified in these regions, being represented in the early or middle Cenomanian of Palestine by the new combination Algorachelus parvus, and in the uppermost Cenomanian of Utah by the new combination Algorachelus tibert. Therefore, a relatively fast and widely distributed geographic dispersion event is recognized, corresponding to the oldest dispersal event so far identified for a lineage of Pleurodira from Gondwana to Laurasia.

A new turtle, Puentemys mushaisaensis, from the middle to late Paleocene Cerrejón Formation of Colombia, is described on the basis of a partial skull and many partial to nearly complete carapaces and plastrons representing multiple ontogenetic stages. Whereas P. mushaisaensis is unique in aspects of its shell morphology, it shares many diagnostic characteristics of bothremydid pleurodirans, including a long exoccipital-quadrate contact, a very low and rounded almost circular carapace, and a thinner internal bone cortex than that of the external cortex in both the carapace and plastron. With a maximum carapacial length of 151 cm, P. mushaisaensis is the largest known bothremydid turtle and represents the first occurrence of bothremydids in the Paleogene of South American tropics. Results from a cladistic analysis of bothremydids indicate that P. mushaisaensis shares a close relationship with Foxemys mechinorum from the Late Cretaceous of Europe, indicating a wide-spread geographical distribution for bothremydines during the Late Cretaceous–Paleocene.

BackgroundBothremydidae is a clade of extinct pleurodiran turtles known from the Cretaceous to Paleogene of Africa, Europe, India, Madagascar, and North and South America. The group is most diverse during the Late Cretaceous to Paleogene of Africa. Little is known, however, about the early evolution of the group.MethodsWe here figure and describe a fossil turtle from early Late Cretaceous deposits exposed at MacFarlane Mine in Cedar Canyon, southwestern Utah, USA. The sediments associated with the new turtle are utilized to infer its stratigraphic provenience and the depositional settings in which it was deposited. The fossil is compared to previously described fossil pleurodires, integrated into a modified phylogenetic analysis of pelomedusoid turtles, and the biogeography of bothremydid turtles is reassessed. In light of the novel phylogenetic hypotheses, six previously established taxon names are converted to phylogenetically defined clade names to aid communication.ResultsThe new fossil turtle can be inferred with confidence to have originated from a brackish water facies within the late Cenomanian Culver Coal Zone of the Naturita Formation. The fossil can be distinguished from all other previously described pleurodires and is therefore designated as a new taxon,Paiutemys tibertgen. et. sp. nov. Phylogenetic analysis places the new taxon as sister to the EuropeanPolysternon provinciale,Foxemys trabantiandFoxemys mechinorumat the base of Bothremydinae. Biogeographic analysis suggests that bothremydids originated as continental turtles in Gondwana, but that bothremydines adapted to near-shore marine conditions and therefore should be seen as having a circum-Atlantic distribution.

Pelomedusoides is the most diverse clade of side-necked turtles and there is an extensive fossil record (de Broin, 1988; Lapparent de Broin, 2000; Gaffney et al., 2006, 2011) that dates back at least to the Barremian (Lower Cretaceous) (Romano et al., 2014). Its large fossil record evidences a greater diversity in the past, particularly at the end of the Mesozoic, and exhibits a good sampling of species that are represented by skull material (Gaffney et al., 2006, 2011). As a consequence, the most complete and recent phylogenetic hypotheses for this clade (e.g. Romano et al., 2014; Cadena, 2015) are based on matrices comprising a great amount of cranial characters derived largely from Gaffney et al. (2006, 2011). In addition, it is well established that shell characters show a lot of phenotypic plasticity, even in the fossil species (Romano, 2008; Gaffney et al., 2006, 2011). In most cases it consequently is not justified to rely on “diagnostic features” of poorly informative shell-only material for describing a new species. Because of that, most authors remark new morphotypes in the literature when such aberrant specimens are recovered, but do not make any nomenclatural act by proposing a new yet poorly supported species (e.g. Romano et al., 2013; Ferreira & Langer, 2013; Menegazzo et al., 2015). Unfortunately, such a supposedly new bothremydid turtle (Pleurodira: Bothremydidae) from the Early Paleocene of Brazil was recently described based on poorly diagnostic remains (Carvalho et al., 2016; hereafter CGB, for the authors initials) and a correction of this unfounded nomenclatural act is required. In addition I present some comments on shell only material from Brazil in order to guide splitter-taxonomists to stop describing poorly preserved fossil specimens as new species.