The French locality of Coderet (latest Oligocene, MP30) yielded an astonishing number of amphibian fossil remains. The studied amphibian assemblage from Coderet consists of 8,639 skeletal remains referred to 10 taxa, making it a hot spot for diversity during the Palaeogene. Urodeles are the dominant group, almost 99% of the fossils, represented by the family Salamandridae, including both subfamilies Salamandrinae and Pleurodelinae. Amongst them, Lissotriton sp. is by far the most abundant taxon (7,139 remains). Other well-represented salamanders include Chelotriton sp. (669 remains), Salamandra sansaniensis (394 remains) and Chioglossa meini (140). Although limb bones and girdle elements in salamanders are generally considered not to be highly diagnostic and rarely allow identification at family or subfamily level, this study shows that they may still display apomorphic features with potential taxonomic value through osteological comparisons of extant, dry disarticulated skeletons. Anurans are less abundant, with only 116 bones, but referred to an astonishing diversity of four families for six taxa: Bufonidae, Discoglossidae ( Latonia ragei and Latonia sp.), Pelobatidae and Ranidae ( Pelophylax sp. and Rana sp.). The biostratigraphy of the amphibians from Coderet is characteristic of the Oligocene and Miocene faunas, confirming a few changes being generally observed between Palaeogene and Neogene European faunas. Nevertheless, this very rich fauna helps to fill temporal gaps in the history of several taxa.
Softshell turtles ( Pan-Trionychidae ) have a particularly rich fossil record in North America, but only a few fragmentary remains have previously been reported from the Oligocene. A review of the literature suggests that Trionyx punctiger and Trionyx leucopotamicus , two taxa previously linked to the Oligocene, should be considered nomen dubia. We report well-preserved trionychid remains from the Early Oligocene (Orellan–Whitneyan) Brule Formation of southwestern North Dakota, including a complete cranium, mandible, and three partial shells that represent a new species of apalonine, Rafetus lysoni . The new species resembles other large-bodied apalonines from the Cenozoic of North America in skull morphology but differs notably in the poor development of carapacial and plastral callosities.
Nowadays, Mediterranean islands are home to several, often endemic, amphibians. Knowledge is limited, however, about amphibian palaeocommunities in the islands and palaeoislands of the Mediterranean Sea, despite the certain presence of fossils in such areas. One case with known but understudied insular amphibian fossils are the Gargano Terre Rosse, a complex of fissures in Southern Italy representing the remaining evidence of a Late Miocene (palaeo)insular fauna. More than 20 years after their first mentions, we offer here detailed descriptions of the fossil amphibians from these fissures, identifying an unbalanced and poorly diversified amphibiofauna largely dominated by Latonia gr. seyfriedi and further composed by Latonia gr. seyfriedi , aff. Latonia gr. seyfriedi , and Pelophylax sp. Notable is the absence of urodeles, reflecting a similar trend in modern Mediterranean islands. Based on preliminary data, it seems that the Terre Rosse amphibiofauna remained generally stable along the history of the palaeoisland, potentially thanks to the resilient and adaptable ecology of the identified taxa and/or a low competition in the insular palaeoenvironment. The absence of remains from the oldest biostratigraphic phase of the Terre Rosse assemblages and the taxonomic uncertainty of the identified anurans hinder any real proposal about the dispersal or areas of origin of these frogs and toads, but their morphology, including potential character mixture, decoupling from continental evolutionary trends in the respective groups, and appearance of unusual features, support them as part of palaeocommunities already affected by evolution in insular contexts.
Radiodont mouthparts (oral cones) are rare in the fossil record compared to the frontal appendages and cephalic carapaces of these iconic early Palaeozoic animals. Therefore, the study of oral cones has primarily been based on their associations with other body parts, from both taxonomic and ecological perspectives. In the Fezouata Biota (Early Ordovician, Morocco), the oral cones are extremely rare; only one fragmented piece has been figured to date, with four plates. Here, we describe two new isolated oral cones with unique morphologies. Based on comparative anatomy with other taxa from the Cambrian, we propose a method using morphometrical data to identify the family and feeding strategy of these two cones and, more broadly, all isolated ones. This approach allows us to place an unidentified oral cone into a family and identify the feeding strategy as either raptorial and benthivores, because no suspension-feeding radiodont oral cone has been found so far. In the Fezouata Biota, the two oral cones probably belong to the Hurdiidae family and they might be benthivores, which is consistent with the frontal appendages known from this locality. Elemental characterisation of both specimens suggests a possible reinforcement of the region around the central opening of the oral cones, which may increase the efficiency of food processing.
The uppermost Aeronian (Llandovery, Lower Silurian) Stimulograptus sedgwickii Biozone, as found in the Guluoping section, Hubei Province, China, and its correlation are discussed. This interval has rarely been recognized in China. The differentiation into the Stimulograptus sedgwickii Biozone and the Stimulograptus halli Biozone, recognized in several regions, is problematic and thus is not used in South China. Stimulograptus sedgwickii , Lituigraptus urceolus , and Parapetalolithus praecedens are among the most common and indicative species for the biostratigraphic interval in the Guluoping section. The graptolite fauna can be referred to the higher part of the Stimulograptus sedgwickii Biozone, but not to the top of the interval. A moderately diverse fauna of biserial and uniserial (monograptid) axonophoran graptolites is described and illustrated. The graptolites are associated with a number of small, possibly lyssacinosidan hexactinellid sponges (?Rossellidae) and remains of indeterminate phosphatic brachiopods. The tectonic deformation makes some graptolite identifications difficult, but new taxa have not been noted.
