James D. Gardner’s research while affiliated with Royal Tyrrell Museum of Palaeontology and other places

An incomplete salamander dentary (AMNH FARB 22965) described herein from the upper Maastrichtian Lance Formation, Wyoming, USA, exhibits a puzzling suite of features. Four features—a prominent bony trough extending anteriorly and curving upwards along the lingual surface of the ramus, lack of an obvious Meckelian fossa or groove, an apparent gap in the tooth row, and a symphysial-like first tooth—are likely anomalies. However, the remaining features are interpreted as normal structures and suggest that AMNH FARB 22965 represents a new genus and species of ba�trachosauroidid, an extinct family of neotenic salamanders that were prominent components of Cretaceous to Neogene freshwater and floodplain paleocommunities in North America and Europe. The new taxon differs from other batracho�sauroidids in a unique suite of dentary and dental features, most notably in having a lingual bony flange paralleling the posterior two-thirds of the dentary tooth row, a prominent and robust coronoid process bearing a grooved anterior face, and the anterior portion of the corpus dentalis behind the symphysis is broadly expanded ventrolingually. The presence of a third batrachosauroidid taxon in the Lance Formation was unexpected, considering that the formation has been well sampled and that its two previously recognized batrachosauroidids, namely Opisthotriton kayi and Prodesmodon copei, are known by abundant isolated bones, including dozens of dentaries, from numerous localities in the unit and elsewhere in the North American Western Interior. Known by a unique dentary from the Bushy Tailed Blowout locality, the taxon represented by AMNH FARB 22965 evidently was uncommon within the Lance Formation paleoenvironment.

Albanerpetontids are an extinct clade of superficially salamander-like lissamphibians that range from the Middle Jurassic (Bathonian)-Early Pleistocene and have a primarily Laurasian distribution. The best Cenozoic record for the clade is in Europe, where two species in the type genus Albanerpeton Estes & Hoffstetter, 1976 occur in over 40 localities of early Oligocene-Early Pleistocene age in Austria, Czech Republic, France, Germany, Hungary, Italy, and Serbia. From the post-evaporitic Messinian (5.41-5.33 Ma or latest Miocene) succession at Moncucco Torinese, in the Piedmont Basin, northwestern Italy, here we describe isolated albanerpetontid jaws and vertebrae referable to A. pannonicum Venczel & Gardner, 2005. This Italian occurrence extends the temporal record for A. pannonicum from the Early Pleistocene and Pliocene back into the latest Miocene and it narrows the temporal gap between that species and its European congener, A. inexpectatum Estes & Hoffstetter, 1976 (early Oligocene-late Miocene).

The Late Cretaceous anuran Hungarobatrachus szukacsi Szentesi & Venczel, 2010 was erected for isolated ilia and tibio-fibulae from the Santonian-age Iharkút locality, in northwestern Hungary. On the strength of ilial features, H. szukacsi was interpreted as a neobatrachian and possible ranoid, making it the only pre-Cenozoic occurrence for both clades in Laurasia. New ilia and the first examples of skull bones (incomplete frontoparietals, squamosals, maxillae, and angulosplenials) from the type locality provide new insights into the taxonomic distinctiveness, osteology, and evolutionary history of H. szukacsi. In addition to its diagnostic ilia (e.g., dorsal crest tall and ornamented laterally with prominent ridges; extensive interiliac tubercle developed across entire medial surface of acetabular region), H. szukacsi is characterized further by having a moderately hyperossified skull exhibiting such traits as frontoparietals, squamosals, and maxillae externally covered with prominent pit-andridge and weakly developed tuberculate ornament (i.e., exostosis), frontoparietals solidly fused along midline, frontoparietals expanded posterolaterally to form a broad squamosal process, squamosals expanded anteroposteriorly to form a plate-like lamella alaris, and maxilla articulating posteriorly with the quadratojugal to form a solid bony ‘cheek’. The first cladistic analysis to include H. szukacsi corroborates its neobatrachian status, but consistently places it among hyloids, rather than ranoids as originally proposed. Indications of hyloids on the African continent and in Madagascar during the Late Cretaceous, suggest that the ancestor of H. szukacsi may have dispersed from Africa, across the proto-Mediterranean and into Europe, prior to the Santonian.

The Late Cretaceous anuran Hungarobatrachus szukacsi Szentesi & Venczel, 2010 was erected for isolated ilia and tibio-fibulae from the Santonian-age Iharkút locality, in northwestern Hungary. On the strength of ilial features, H. szukacsi was interpreted as a neobatrachian and possible ranoid, making it the only pre-Cenozoic occurrence for both clades in Laurasia. New ilia and the first examples of skull bones (incomplete frontoparietals, squamosals, maxillae, and angulosplenials) from the type locality provide new insights into the taxonomic distinctiveness, osteology, and evolutionary history of H. szukacsi. In addition to its diagnostic ilia (e.g., dorsal crest tall and ornamented laterally with prominent ridges; extensive interiliac tubercle developed across entire medial surface of acetabular region), H. szukacsi is characterized further by having a moderately hyperossified skull exhibiting such traits as frontoparietals, squamosals, and maxillae externally covered with prominent pit-andridge and weakly developed tuberculate ornament (i.e., exostosis), frontoparietals solidly fused along midline, frontoparietals expanded posterolaterally to form a broad squamosal process, squamosals expanded anteroposteriorly to form a plate-like lamella alaris, and maxilla articulating posteriorly with the quadratojugal to form a solid bony ‘cheek’. The first cladistic analysis to include H. szukacsi corroborates its neobatrachian status, but consistently places it among hyloids, rather than ranoids as originally proposed. Indications of hyloids on the African continent and in Madagascar during the Late Cretaceous, suggest that the ancestor of H. szukacsi may have dispersed from Africa, across the proto-Mediterranean and into Europe, prior to the Santonian.

Albanerpetontids are an extinct clade of salamander-like lissamphibians characterised by features such as fused frontals and sculptured skull roof bones. Here we provide a histological analysis of the fused and sculptured frontals in two Late Cretaceous species of the type genus Albanerpeton sensu lato that differ in body size: moderate-sized ‘Al.’ gracile and larger-sized ‘Al.’ nexuosum. Despite general similarities in microanatomy/histology (no sutural trace remains between left and right frontals; sculpture formed by appositional growth of bone; predominance of parallel-fibred bone; and lack of growth marks, secondary osteons, and Sharpey’s fibres) and the presence of sub-ventrolateral crest canals (possible albanerpetontid synapomorphy), ‘Al.’ nexuosum differs from ‘Al.’ gracile in exhibiting: a distinct three-layered diploë structure; bone remodelling; a higher degree of vascularisation; and more numerous osteocytic lacunae. We suggest that (1) histological differences between ‘Al.’ gracile and ‘Al.’ nexuosum are related to differences in absolute body sizes and relative development of sculpture and robustness of frontals and (2) the sub-ventrolateral crest canals in albanerpetontids are homologous to the canalis arteriae orbitonasalis in modern anurans. Two features (internal vascularisation and lack of Sharpey’s fibres) support a recent suggestion that albanerpetontids may have relied entirely on cutaneous respiration.

Osteological information for extant amphibians and reptiles is scattered through numerous papers and books; this hinders a precise perception of what is known and what is not. In order to aggregate in a synthetic way the available published information and to determine which taxa and topics warrant further attention, we started to compile an online database that records, besides the species and where its osteology is presented, the following key data: anatomical region documented, intraspecific variation (e.g., individual, ontogenetic, sexual), nature of the information (e.g., description, figure or table, scoring for cladistic analysis, measurements for geometric morphometrics or finite element analysis), type of preparation/source of the information (e.g., dry skeleton, clearing and staining, tomography, X-rays, histological section), number of specimens analyzed, and if the osteological information is associated with the description of a new species. The first published work on this topic appears to be “De quadrupedibus digitatis […]” issued posthumously in 1637 by Aldrovandi, which depicts, among others, a partial skeleton of Salamandra salamandra next to the whole animal, as well as a skull of Caretta caretta. The osteology for most of the currently recognized 80 amphibian and 144 European reptile species (see Sillero et al. 2014) has been at least partially described in about 300 publications so far: 72 amphibians and 118 reptiles. Despite this broad taxonomic coverage, few European species have detailed descriptions for their entire skeleton as most accounts are focused on the skull, with the exception of urodelans (mostly vertebrae) and turtles (mostly shell).

We report diagnostic, albeit fragmentary, material representing the earliest known appearance of the only extant bowfin subfamily, the Amiinae, from the Mussentuchit Member of the Cedar Mountain Formation, in central Utah, U. S. A. The remains occur at the Early–Late Cretaceous boundary, having been dated to the latest Albian–earliest Cenomanian by Cifelli et al. (1997), with a mean 40Ar/39Ar radiometric age of 98.39 ± 0.07 Ma. This predates the former oldest record of the Amiinae, from the middle member of the overlying Cenomanian Dakota Formation of Utah (Brinkman et al. 2013), and includes cranial material, complementing our previous knowledge of the anatomy of early amiines. It additionally demonstrates that the Late Cretaceous aspect of the fauna noted by Cifelli et al. (1999) is also reflected in its freshwater component. Recovered specimens include a well-preserved dentary in articulation with a fragmentary articular, and isolated centra and teeth, all of which can be reliably identified, and represent an amiine of essentially modern morphology. This material was found alongside another amiid centrum of a different morphology, similar to isolated centra previously described by Brinkman et al. (2013). This indicates that at least two different bowfin taxa were present at the time of deposition. A fragmentary tooth plate bearing blunt teeth, and isolated, similarly blunt styliform teeth were also recovered, and may represent amiid material as well, although these could alternatively represent semionotiform or pycnodontiform material.

Sedimentary basins in Anatolia preserve a rich record of Neogene terrestrial environments at the crossroads between Asia and Europe. Deciphering the geological evolution of these basins is essential for understanding how this fine record came to be preserved. In a reciprocal fashion, the fossil record allows for correlating between basins and for reconstructing environmental evolution in the region. Culmination of Tauride orogeny in SW Anatolia was followed by a NW-SE extension from late Miocene onward that created a broad array of NE-trending orogen-top basins comprised of tripartite basin-fill successions, including alluvial-fan, fluvial and lacustrine deposits. The initial infilling of these deep basins is documented by a transition from coarse-clastic alluvial fans and channelized, axial fluvial systems into central shallow-perennial lakes. These deposits contain macromammal fossil assemblages indicating an early Turolian (MN11-12; late Tortonian) age. By the early Pliocene, more humid climatic conditions and a rise in the local base-level resulted in the rapid expansion of lakes. The base of this lacustrine succession is marked by marsh-swamp deposits containing a diverse micromammal assemblage indicating a late Ruscinian (late MN15; late Zanclean) age. Subsequent deepening of the lakes was prompted by a second pulse of rifting during WNW-ESE extension and is documented by thick and laterally extensive marl successions. These deep lakes later shrank due to renewed progradation of alluvial fans and eventually dried out. The top of the complete lacustrine succession also is represented by marsh-swamp deposits, which contain a diverse micromammal assemblage indicating an early Pleistocene (MN17; latest Villanyian) age. In the late Pleistocene, a third pulse of extension caused complex deformation that locally re-arranged the basins into its present-day configuration. New age controls provided by mammal assemblages within the succession are important for calibrating and placing the palaeoenvironmental evolution of the Anatolian terrestrial basins into a regional palaeogeographic framework.