Cardichelyon rogerwoodi is an enigmatic fossil turtle from the late Paleocene to early Eocene of North America. Previous analyses suggested affiliation with Testudinoidea, in particular the big-headed turtle Platysternon megacephalum, based on the presence of multiple musk-duct foramina and a large head. We here highlight previously undocumented characteristics for this turtle, notably the presence of short costiform processes, a rib-like axillary process, and a posterior plastral hinge. Phylogenetic analysis places Cardichelyon rogerwoodi within Testudinoidea, but the exclusion of testudinoids suggest an affiliation with Dermatemydidae. Using consilience with external data we favor placement within Kinosternoidea. Cardichelyon rogerwoodi is therefore an aberrant, hinged kinosternoid that developed in situ in North America during the Paleocene long before the arrival of testudinoids on this continent in the early Eocene.

A new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar.

New shell material of a trionychid turtle from the Upper Cretaceous (upper Campanian) Fossil Forest Member of the Fruitland Formation of northwestern New Mexico represents a new species, Gilmoremys gettyspherensis. The material consists of right costals I–III, V, VI, and VIII, left costals V, VII, and VIII, the left half of the entoplastron, the right hypo- and xiphiplastron, and the left hyo-, hypo-, and xiphiplastron. The specimen shows great similarities to the Late Cretaceous (Maastrichtian) trionychid Gilmoremys lancensis (Gilmore, 1916) by having a relatively thin shell, carapacial sculpturing consisting of fine pits combined with extended sinusoidal ridges or grooves, free costal rib ends, presence of a preneural, a distally constricted costal I and distally expanded costal II, two lateral hyoplastral processes, low hyoplastral shoulders, and full midline contact of the elongate xiphiplastra, but differs by being smaller, having raised sinusoidal ridges on the carapace instead of grooves, less distally expanded costals II, and less elongate xiphiplastra. Phylogenetic analysis places Gilmoremys gettyspherensis n. sp. as sister to Gilmoremys lancensis near the base of the clade Plastomenidae. Like the majority of previously described plastomenid materials, the type specimen of Gilmoremys gettyspherensis n. sp. was collected from a mudstone horizon, suggesting a preference for ponded environments.

UUID: http://zoobank.org/e7165061-d86b-46b7-a1f8-c31f5a8ed628

New cranial and postcranial material of the baenid turtle Neurankylus from the Paleocene Nacimiento Formation (Torrejonian NALMA) of northwestern New Mexico represents a new species, Neurankylus torrejonensis. The material consists of a fragmented but mostly complete skull, a partial carapace and plastron, portions of both humeri, a partial pelvis, a complete right femur, and a distal phalanx. The small, undivided cervical scale, wide vertebrals, complete ring of marginals, and large size (carapace length 520 mm) diagnose the new taxon as belonging to Neurankylus. The narrow fifth vertebral scale and scalloped posterior shell margin reveal affinities with Neurankylus baueri Gilmore, 1916, which is known from Campanian sediments in New Mexico and Utah. The holotype of Neurankylus torrejonensis is the youngest known specimen of the Neurankylus lineage, which is known to reach at least back to the Late Cretaceous (Santonian). A nearly complete species-level analysis of baenids confirms the basal placement of Neurankylus outside of Baenodda and the split of Baenodda into two primary subclades, herein named Palatobaeninae and Eubaeninae.

We present a rank-free phylogenetic nomenclature for 25 well-established ancient clades of living turtles. This is the first attempt to document fully the nomenclatural history of a clade with the intent of proposing a coherent nomenclatural system to replace the traditional rank-based nomenclature. Because of the imperative to retain connectivity to the literature for information retrieval, due consideration is given to balancing the desire to develop a consistent system against the desire to conserve traditional associations between names, taxa (i.e., clades), and characters. Novel issues and problems that emerged during this review include: the unclear name/clade association of traditional names; the creation of synonymy lists from which to choose a name; difficulties associated with selecting a single criterion for choosing among multiple ‘subjectively synonymous’ names; identifying authorship for a converted traditional name; and the potential loss of nomenclatural information due to ‘functional homonyms.’ This work may provide a useful road map to those intent on converting their traditional rank-based nomenclatures to explicitly phylogenetic nomenclatures under the precepts of the PhyloCode.

A near complete shell from the Hemphillian 4 (Miocene/Pliocene boundary) Buis Ranch local fauna of Beaver County, Oklahoma, represents a fossil box turtle. An anterior contact of neural III and neural V with costal III and costal V only, respectively, presence of a small contact between the suprapygal and eleventh peripherals, development of a thin peripheral lip for articulation with the posterior plastral lobe, placement of the vertebral III/IV sulcus on neural VII, presence of two anterior musk duct glands, a rounded posterior plastral lobe, an elongate shell outline, and a complete neural series diagnose the fossil as a new species, Terrapene parornata n. sp. A phylogenetic analysis of fossil box turtles places T. parornata along the phylogenetic stem of the extant taxon T. ornata. The holotype of ‘Terrapene longinsulae’ cannot be distinguished from Terrapene ornata and is therefore synonymized. Finally, ‘Terrapene’ corneri lacks characters of crown group Terrapene and may therefore represent a stem box turtle. The provenance of the holotype of ‘Terrapene longinsulae’ is more poorly known than previously recognized and this specimen may originate from Kansas or Nebraska and be early Miocene to late Pleistocene in age. Terrapene parornata is therefore the oldest demonstrable representative of crown group Terrapene (ca. 5.3–4.6 Ma). ‘Terrapene’ corneri from the late Barstovian of Nebraska and fragmentary material from the middle Barstovian of Nebraska by contrast are the oldest representative of the Terrapene lineage (ca. 14.5–11.5 Ma). A review of morphological characters related to shell kinesis reveals that most are highly correlated. The results of the phylogenetic analysis converge upon those of molecular data when these correlated characters are omitted from the analysis.

A complete skeleton of Solnhofia parsonsi (Cryptodira, Eurysternidae) from the Kimmeridgian/Tithonian boundary of Schamhaupten, Germany provides the first complete understanding of the postcranial morphology of this genus. The here newly described postcranial characters are important in distinguishing Solnhofia from shell-based genera and thus help in resolving part of the parataxonomic conflict between shell-based and cranium-based turtle genera. This disparity originated during the last 150 years due to the history of fossil finds, preparation, and changing interests of researchers. Synonymies of Solnhofia with such turtle genera as Eurysternum, Idiochelys, Plesiochelys, Thalassemys, and Euryaspis can now be refuted. Similarities with Hydropelta are apparent, but not considered sufficient to support a synonymy. Newly observed or confirmed characters include the relatively large head (40 percent of the carapace length), the pentagonal carapace, the unique arrangement of bones and fontanelles in the pygal region, and the absence of mesoplastra, epiplastra, and an entoplastron.

The carcass of the new specimen was embedded in finely laminated limestones and shows little sign of disintegration or scavenging, suggesting hostile bottom conditions with very low water energy during deposition. This taphonomy agrees with recent published models for the origin of the lithographic limestones of southern Germany. Tooth marks along the posterior margin of the carapace are evidence of predation by a broad-nosed crocodilian. This is the first clear example for this type of predatorial interaction from the Upper Jurassic of Germany.

Testudo antiqua is one of the few fossil turtle names to have survived the past 200 years of taxonomic reshuffling with its original genus and specific epithet intact. The nine currently known specimens were collected from the middle Miocene Hohenhöwen locality in southern Germany. Because the available Hohenhöwen material was never fully described, we here completely document all known specimens. It is unclear which of these specimens formed the original T. antiqua type series, so we herein selected the best preserved representative as the neotype. A phylogenetic analysis places T. antiqua in a basal polytomy within the clade Testudo, indicating that T. antiqua may represent the ancestral morphology of Testudo. As with a number of other published studies, ours was unable to resolve relationships between the three extant Testudo lineages (the hermanni-group, the graeca/kleinmanni/marginata group, and the horsfieldii-group). Finally, with a view toward locating more turtles and in order to better understand the geological and ecological context of these tortoises, we visited Hohenhöwen several times to search for the original collection sites, but we were unable to locate the original fossil quarries described in the literature.

The terrestrial tortoise clade Chelonoidis is endemic to the South American continent and nearby islands. Three continental species are currently recognized that inhabit three distinct habitats. The red-footed tortoise (C. carbonaria) and yellow-footed tortoise (C. denticulata) are often sympatric tropical to semi-tropical taxa, but the former taxon generally prefers open and wet savannahs, whereas the latter distinctly prefers permanent and wet forest cover. In contrast, the Chaco Tortoise, C. chilensis, is arid-adapted and lives along the eastern dry slopes of the southern Andes (Ernst and Barbour, 1989). The diverse group of generally dry-adapted tortoises from the Galapagos Islands is currently thought to be the gigantic sisters of C. chilensis (Caccone et al., 1999).

Turtles have served as a model system for molecular divergence dating studies using fossil calibrations. However, because some parts of the fossil record of turtles are very well known, divergence age estimates from molecular phylogenies often do not differ greatly from those observed directly from the fossil record alone. Also, the phylogenetic position and age of turtle fossil calibrations used in previous studies have not been adequately justified. We provide the first explicitly justified minimum and soft maximum age constraints on 22 clades of turtles following best practice protocols. Using these data we undertook a Bayesian relaxed molecular clock analysis establishing a timescale for the evolution of crown Testudines that we exploit in attempting to address evolutionary questions that cannot be resolved with fossils alone. Some of these questions, such as whether the turtle crown originated in the Triassic or Jurassic, cannot be resolved by our analysis. However, our results generate novel age-of-origination estimates for clades within crown Testudines. Finally, we compare our fossil calibrations and posterior age estimates to those from other studies, revealing substantial differences in results and interpretation.

New Palatobaena material from the Hell Creek Formation (Maastrichtian), including the first skull and shell association, from southwestern North Dakota represents a new species named herein Palatobaena cohen. the material consists of 4 skulls, 2 lower jaws, and 2 shells and represents a true biological population (spatially and temporally restricted), which provides unprecedented access to ontogenetic and other intraspecific variation found in this taxon. the skull's round shape and lack of a lingual ridge on the greatly expanded triturating surface indicate its Palatobaena affinities, but it differs from both previously existing Palatobaena taxa in a number of features. the addition of shell characters to the most inclusive baenid phylogenetic analyses (Maximum parsimony and Bayesian) to date indicate that Pa. cohen is sister taxon to the other Palatobaena taxa. Notably, both the maximum parsimony analysis and Bayesian analysis provide strong support for Plesiobaena antiqua as sister to the Palatobaena clade. in addition, both analyses provide strong support for Stygiochelys estesi as sister to the Eocene clade of Baena arenosa and Chisternon undatum, which significantly reduces this clades' ghost lineage. the baenid topology reveals a demonstrably homoplastic trend towards the reduction of the temporal emargination and unique thickening of the posterior portion of the parietals that corresponds with the K/T boundary and is hypothesized to have provided limited protection from increasingly effective mammalian predators.

The skull of the enigmatic turtle Compsemys victa Leidy, 1856 is described. A number of unique characteristics are apparent, including the extremely thick nature of all cranial bones, the presence of rod-like epipterygoids, placement of the foramen posterius canalis carotici interni halfway along the contact between the pterygoid and basisphenoid, lack of cheek emarginations, and the reduction of the size of the cavum tympani relative to the orbit. Two differing global turtle analyses and one paracryptodiran analysis were performed to determine the phylogenetic placement of C. victa. Both global analyses converged by placing C. victa within Paracryptodira, herein defined as the most inclusive clade that includes Pleurosternon bullockii and Baena arenosa, but no species of living turtle, whereas the paracryptodiran analysis places C. victa outside of Baenoidea, herein defined as the least inclusive clade that contains P. bullockii and B. arenosa. Although a number of similarities are apparent between C. victa and the uncommon, extant testudinoid Platysternon megacephalum, the available data indicate that these similarities are convergent, likely due to their carnivorous diet. Taphonomic evidence reveals that basal paracryptodires, including C. victa, preferred slow moving or ponded water environments. The riverine habitat preference of baenodds must therefore be derived.