Postcranial anomalies of Eocene freshwater pleurodiran and cryptodiran turtles from the Spanish Duero Basin.

Testudines are one of the best-represented taxonomic groups among the Paleogene taxa of the Duero Basin (Castile and Leon Autonomous Community, central Spain). Among them, Neochelys (Podocnemidide) and Allaeochelys (Carettochelyidae) are most abundant, allowing the population to be assessed for osteological anomalies. The abundance of postcranial remains of both taxa allows us to identify several individuals with potential anomalies, mostly in their shells. Some of them have already been described in previous studies, but most of them are still unpublished. The objective of this study is to analyze in detail the anomalous Neochelys and Allaeochelys remains. As a result, different categories of causal agents (such as bacteria, fungi, parasites, or trauma) have been identified as potential producers of the anomalies in these freshwater turtles. Information regarding the pathogenesis and healing stages of some of these anomalies is provided.

A bothremydid turtle (Pleurodira) from the middle Cenomanian of Vale de Figueira (Belas, Portugal).

An unpublished turtle shell from the middle Cenomanian of Vale de Figueira, near Belas (Lisbon District, Portugal), is recognized by us as collected in 1880 under the direction of Carlos Ribeiro. No turtle remains from that region had so far been figured, described or discussed from a systematic point of view. The specimen corresponds to a partial but articulated shell. It is attributed to Pleurodira and, more specifically, to Bothremydidae. Only one pre-Campanian turtle specimen was previously identified at the infrafamilial level in the Cretaceous record of Portugal. It was a partial shell from the middle Cenomanian of Nazaré (Leiria District) attributed to the bothremydid Algorachelus peregrina, a species defined in a Spanish synchronous locality (Algora, in Central Spain). Several anatomical regions in the specimen from Vale de Figueira were not preserved in the partial carapace from Nazaré, and differences in the morphology of some elements are recognized between both shells. However, the individual studied here is also ascribed to Algorachelus peregrina, these differences being justified by intraspecific variability. Therefore, the specimen represents the second evidence on the species in Portugal, being the only one recognized for the Lisbon District.

A new Crocodyloidea from the middle Eocene of Zamora (Duero Basin, Spain).

The eusuchian crocodyliforms recorded in the Eocene levels of the Spanish Duero Basin belong to three lineages: Planocraniidae, with the species Duerosuchus piscator; Alligatoroidea, represented by several specimens of the genus Diplocynodon; and Crocodyloidea, which includes several specimens traditionally attributed to Asiatosuchus. The genus Asiatosuchus, established in 1940 based on a middle Eocene species from Mongolia, has subsequently served as a wastebasket taxon for Paleogene remains belonging to several species, not only from Asia but also belonging to the European and North American records. Many of these species are known by highly fragmentary remains, sharing the presence of characters such as a flat and triangular skull, and long symphyses in the lower jaw, recognized as characteristic for the crocodyloids. In addition to isolated cranial remains, among the material traditionally attributed to Asiatosuchus at the Duero Basin stands out a nearly complete skull and a left mandible, from the middle Eocene area of Casaseca de Campeán (Zamora Province). The present study analyses in detail these specimens, previously reported during the 1980s, but analyzed in a very preliminary way. They are included for the first time in a phylogenetic analysis to establish the systematic position of this Spanish form. The results confirm that it corresponds to a new species of basal crocodyloid, defined here as Asiatosuchus oenotriensis sp. nov.

A pan-cheloniid turtle from the Middle Miocene of Portugal.

Currently, there is no information on the fossil record of Pan-Cheloniidae from the Neogene of the Iberian Peninsula. A well-preserved partial skeleton attributable to this lineage of turtles, from the Middle Miocene of Portugal, is presented here. It preserves much of the anterior half of its carapace, in which the plates remain articulated, as well as several articulated dorsal vertebrae, and an isolated cervical and a caudal vertebrae. The analysis of this Serravallian find shows that it cannot be attributed to a hitherto described taxon. Thus, a new member of Pan-Cheloniidae is defined, Lusochelys emilianoi gen. et sp. nov., improving the relatively limited knowledge about this lineage for the Middle Miocene global record. It represents the first generic and specific systematic attribution for a member of Pan-Chelonioidea in the Neogene record of the Iberian Peninsula.

The turtles from the middle Paleolithic site of Gruta Nova da Columbeira (Bombarral, Portugal): Update through an archaeozoological perspective.

Twenty-five years after the preliminary systematic study of the turtle remains (Agrionemys [=Testudo] hermanni and Emys or Mauremys) recovered from Gruta Nova da Columbeira site (Bombarral, Portugal), the results of its review from systematic and archaeozoological perspectives are presented here. Tortoise remains studies from pre-Upper Paleolithic sites worldwide have provided relevant data confirming its role as a dietary supply for hominid populations and informing about their ability to adapt to local environmental resources. The Iberian Peninsula record in general, and specifically, that from Portugal, have yielded substantial evidence to this highly debated topic. In this sense, turtle remains recovered in Gruta Nova da Columbeira site, discovered in the 1960s and the main ensemble chronologically ascribed to the MIS-5 (87.1 ± 6.3 ka BP), offer new information to this debate. Its detailed restudy, has allowed us the identification, justification, and figuration of remains attributed to two Iberian turtle taxa, Chersine hermanni and Emys orbicularis. Therefore, this update on the data concerning the turtle record from Gruta Nova da Columbeira provides new justified taxonomic evidence regarding the Iberian turtle taxa distribution during the Upper Pleistocene. The previously suggested hypothesis about the tortoise human consumption on the site is here evaluated through the development of an archaeozoological and taphonomical analysis, as well as considering the potential documentation of anthropic alterations (e.g., burning, cutmarks, percussion marks). In this sense, this hypothesis is confirmed. In addition, the presence of carnivore activity evidence indicates the engagement of other agents in the deposit formation.

A New Species of the Pythonomorph Carentonosaurus from the Cenomanian of Algora (Guadalajara, Central Spain).

The Cenomanian (lowermost Upper Cretaceous) faunal assemblages are of high interest in understanding the turnovers that took place between the Early and the Late Cretaceous, resulting in significant differences. In this context, the analysis of the association of reptiles found in the Algora fossil site (Guadalajara Province, Central Spain) is of great interest since it represents the first European Cenomanian site with a high concentration of macrovertebrate remains. A new pythonomorph 'lizard' from Algora, Carentonosaurus algorensis sp. nov., is described here. It is the second representative of this European genus. Its microanatomical study reveals that an extreme pachyosteosclerosis affected at least its dorsal vertebrae, suggesting adaptations for slow-swimming habits in shallow-water environments. Consequently, this new taxon is interpreted as a slow swimmer, hovering near the bottom of near-shore marine environments of the Late Cretaceous European Archipelago and, more specifically, along the shores of the larger Iberian Island for that period. This is in concordance with the high diversification of 'pachyostotic' pythonomorphs recorded during the Cenomanian, allowing the subsequent adaptation of this lineage to open marine environments.

Shell characterization of the youngest valid species of the European Eocene genus Neochelys (Pleurodira, Podocnemididae): The Spanish Bartonian Neochelys salmanticensis.

The freshwater pleurodiran turtle Neochelys is the best-represented member of Podocnemididae in the European record, being known by eight Eocene species. The youngest of them is the Bartonian (middle Eocene) Neochelys salmanticensis, from the Duero Basin (Salamanca Province, Central Spain). It corresponds to the largest representative known for this genus, its shell reaching 50 cm in length. Despite this form was defined several decades ago, the information currently available on it is very limited, being restricted to shell remains of less than 10 individuals. In fact, this species lacks a valid diagnosis, considering the current knowledge about the genus. Numerous remains (i.e., more than 1,200) of the shell of this Spanish species are identified. Its detailed study is presented here, so that the anatomy of its shell is characterized in detail. In addition, several aspects related to its intraspecific variability are analyzed, relative to the individual, ontogenetic, and sexual variability. In this way, the shell of N. salmanticensis can be characterized with greater precision than that of any other species of the genus.

Neuroanatomical study of the podocnemidid turtle Neochelys arenarum (Pleurodira), from the early Eocene of France.

Neochelys is an exclusively European Eocene podocnemidid genus belonging to a linage that reached this continent at the early Eocene. The so far available anatomical information about it is relatively abundant, especially considering that of its shell, at least partially preserved for the eight valid species currently considered. By contrast, the skull of very few representatives of the taxon has been identified. Neochelys arenarum is one of the species for which the cranial anatomy is known. It corresponds to the oldest species of this genus, coming from the MP7 zone of the Ypresian (early Eocene) of Southern France. The 3D virtual cranial reconstruction and the detailed neuroanatomical study of a representative of Neochelys are carried out here for the first time based on that species, this being also the first study of this nature performed for a European podocnemidid. In addition, the comparison of the neuroanatomical structures (i.e., the endocranial and labyrinthic cavities, and the nervous and circulatory canals) of N. arenarum with those of other representatives of Podocnemidoidae has been achieved.

The oldest evidence of Testudo graeca (Testudinidae) in the Iberian Peninsula.

The Testudo graeca (i.e., Greek Tortoise or Spur-thighed Tortoise) origin in Western Europe is a subject of debate within the scientific community. The species is a part of the current Spanish biodiversity, with three isolated populations, located in the south-eastern (Almeria and Murcia) and south-western (Doñana National Park, Andalusia) areas of the Iberian Peninsula, and in the Mallorca Island (Balearic Islands). Throughout the 19th and 20th centuries, putative references to the presence of Testudo graeca in the Iberian paleontological and archaeozoological records were relatively common. However, many of them were refuted in subsequent papers and, those that were not, are currently considered as doubtful. The aim of this work is to present and describe the oldest indisputable remains of Testudo graeca in the Iberian Peninsula. They correspond to several individuals, hitherto unpublished, recovered as grave goods in two tombs at the Plaza Marqués de Busianos 5 site (Valencia, eastern Spain), dated between the first and second centuries AD.

A lower Pliocene Erymnochelyini turtle (Pleurodira, Podocnemididae) from the Democratic Republic of Congo.

The presence of a pleurodiran turtle putatively attributable to Erymnochelys madagascariensis (i.e., the only representative of Erymnochelyini that is part of the current biodiversity) or to a closely related form was recognized, in the early 1990s, for the Lower Pliocene record of the Sinda-Mohari region (Democratic Republic of Congo). The material attributable to it was restricted to postcranial remains. Although some elements of the anterior region of the skull were subsequently found, this taxon had not been analyzed in detail until now. Knowledge about Erymnochelyini has increased remarkably since the 1990s and, especially, during the 21st century. The taxon from the Democratic Republic of Congo is here analyzed in detail, not only considering current knowledge about the lineage but also incorporating new material into this study, highlighting several partial skulls. Thus, it corresponds to one of the members of this lineage represented by a greater number of skulls. It is attributed to a new taxon, Mokelemys mbembe gen. et sp. nov., being the only representative of Erymnochelyini currently known for the Pliocene record.

The neuroanatomy of the bothremydid pleurodiran turtle Galianemys, from the Late Cretaceous (Cenomanian) of Morocco.

Galianemys is one of the three genera of Cearachelyini (Pleurodira, Bothremydidae) so far defined, being the only one identified in Africa (in the Cenomanian of Morocco). It is represented by two species, Galianemys whitei and Galianemys emringeri, both being identified by several skulls. The other two representatives of Cearachelyini are both South-American forms, and only the species Cearachelys placidoi (from the Albian of Brazil) preserves cranial remains, including a partial skull corresponding to its holotype. However, despite the relatively great number of skulls identified for both Galianemys spp. and Cearachelys placidoi, information about the neuroanatomy of this lineage is very limited. The three-dimensional (3D) reconstruction of the skulls of two specimens belonging to the genus Galianemys, each of them representing a different species, is performed here for the first time. All of the cranial bones of one of them are also virtually reconstructed to accurately characterize them. In addition, the 3D models of the main neuroanatomical structures (i.e., cranial, nasal, and labyrinthic cavities, and nervous and carotid canals) of both specimens were generated, most of them being described in detail for first time in Cearachelyini. Neuroanatomical differences are recognized when the skulls of both species of Galianemys analyzed here are compared. In addition, the comparison between the neuroanatomy of Galianemys spp. and that of other non-Cearachelyini bothremydids allow us to identify some differences between those lineages, but also recognize other shared characters for the entire lineage of Bothremydidae, to providing a more precise characterization within Pleurodira.

Analysis of shell anomalies in the Spanish upper cretaceous basal pan-pleurodire Dortoka vasconica (Dortokidae).

The study of pathological bone modifications of extinct organisms of lineages, which are still living today, in combination with extant representatives, allows to infer data about population dynamics, lifestyle, and diseases they were subject to. Pathological studies in turtles are extensive; however, these contributions are mainly focused on extant representative records of survival rates or on non-skeletonized material, and do not generally include morphological descriptions, illustrations, or data concerning their etiology and pathogenesis. As a consequence, paleopathology in turtles remains relatively poorly understood, especially considering extinct forms. In this context, we herein analyze marks of possible pathological origin recognized in two disarticulated plastral plates of the Spanish freshwater basal pan-pleurodiran turtle Dortoka vasconica (Dortokidae), from its type locality, the Upper Cretaceous (late Campanian-early Maastrichtian) fossil site of Laño 1 (Treviño County, Burgos, Spain). As a result, information regarding the possible etiology, pathogenesis, and stages of healing of the marks studied here are provided. A probable infectious origin is recognized as the etiology in both plates, these marks being considered as pathologies. This study contributes to our understanding of pathologies in extinct turtle taxa, specifically a stem-pleurodiran turtle.

Surviving the Cretaceous-Paleogene mass extinction event: A terrestrial stem turtle in the Cenozoic of Laurasia.

Findings of terrestrial stem turtles are not uncommon at Mesozoic continental sites in Laurasia, especially during the Upper Cretaceous. Thus, the record of several lineages is known in uppermost Cretaceous ecosystems in North America (Helochelydridae), Europe (Helochelydridae and Kallokibotion) and Asia (Sichuanchelyidae). No terrestrial stem turtle had been described in Laurasia after the Cretaceous-Paleogene mass extinction event. Thus, the only representatives described in the Cenozoic record worldwide corresponded to forms from southern Gondwana, where some of them survived until the Holocene. A bizarre terrestrial stem turtle from the upper Thanetian (upper Paleocene) of Europe is described here: Laurasichersis relicta gen. et sp. nov. Despite its discovery in France, in Mont de Berru (Marne), this Laurasian taxon is not recognized as a member of a European clade that survived the Cretaceous-Paleogene extinction event. It belongs to Sichuanchelyidae, a hitherto exclusively Asian Mesozoic group, known from the Middle Jurassic. Finds at the Belgian site of Hainin (Hainaut) show that this dispersion from Asia and the occupation of some niches previously dominated by European Mesozoic terrestrial stem forms had already taken place a few million years after the mass extinction event, at the end of the lower Paleocene.

New highly pachyostotic nothosauroid interpreted as a filter-feeding Triassic marine reptile.

Two well-preserved specimens of a new eosauropterygian from the Upper Triassic of Central Spain are attributed to a new taxon, Paludidraco multidentatus gen. et sp. nov. It is a member of Simosauridae that presents several exclusive characters suggesting a highly specialized trophic adaptation. This discovery increases the already high ecological disparity of the Triassic marine reptiles.

A new turtle confirms the presence of Bothremydidae (Pleurodira) in the Cenozoic of Europe and expands the biostratigraphic range of Foxemydina.

Pleurodira is a clade of Gondwanan turtles that reached Europe at the beginning of the Late Cretaceous. It is recognized as the most abundant and diverse group of freshwater turtles in the uppermost Cretaceous record of this continent, being represented by several members of Bothremydidae. Two well-preserved and relatively complete skulls are studied in this paper. They come from lower Eocene levels of the French locality of Saint-Papoul (Aude). These specimens are recognized as attributable to a new taxon, Tartaruscola teodorii gen. et sp. nov., identified as a bothremydid. This new form constitutes the only known unambiguous and valid representative of Bothremydidae in the Cenozoic of Europe. The new taxon is diagnosed by several autapomorphies and also by an exclusive combination of characters. It is one of the few members of Bothremydini identified in the Cenozoic record and the only one described for the Eocene outside of the Ouled Abdoun Basin of Morocco. Tartaruscola teodorii is identified as a member of Foxemydina, a clade recognized here as exclusive of the European record, and whose presence in post-Mesozoic levels is demonstrated in this paper. The European Foxemydina T. teodorii and the African Bothremydina Bothremys kellyi, both from the Ypresian, are the youngest members of Bothremydini hitherto known.

New Crocodyliforms from Southwestern Europe and Definition of a Diverse Clade of European Late Cretaceous Basal Eusuchians.

The late Campanian-early Maastrichtian site of Lo Hueco (Cuenca, Spain) has provided a set of well-preserved crocodyliform skull and lower jaw remains, which are described here and assigned to a new basal eusuchian taxon, Lohuecosuchus megadontos gen. et sp. nov. The reevaluation of a complete skull from the synchronous site of Fox-Amphoux (Department of Var, France) allows us to define a second species of this new genus. Phylogenetic analysis places Lohuecosuchus in a clade exclusively composed by European Late Cretaceous taxa. This new clade, defined here as Allodaposuchidae, is recognized as the sister group of Hylaeochampsidae, also comprised of European Cretaceous forms. Allodaposuchidae and Hylaeochampsidae are grouped in a clade identified as the sister group of Crocodylia, the only crocodyliform lineage that reaches our days. Allodaposuchidae shows a vicariant distribution pattern in the European Late Cretaceous archipelago, with several Ibero-Armorican forms more closely related to each other than with to Romanian Allodaposuchus precedens.