We document several ammonoid taxa from the lowermost Aegean (lower Anisian) of the Deşli Caira B section, Dobrogea (Romania), candidate section for the GSSP of the Anisian stage. The specimens were collected from beds 2827 and 822A2, and include the new genus Simionescuites, with three new species, i.e., S. dobrogeanus n. gen. n. sp, S. laevicostatus n. gen. n. sp, and S. nodiumbilicatus n. gen. n. sp; Longobarditoides caucasius Shevyrev, 1961; Pseudosageceras sp. ind.; and Sageceras sp. ind. In addition, seven specimens are assigned to Stenopopanoceras transiens Tozer, 1972.Integration of these new taxa with those described from the same stratigraphic interval by Balini et al. (2024) demonstrates that Stenopopanoceras transiens is the most common, short-ranging species within the interval between sample 822A2 Lower and 822A2 Upper. On this basis, a revision of the Paracrochordiceras–Japonites beds recognized in Chios (Greece) by Assereto (1974) is proposed. The Stenopopanoceras transiens subzone is herein established as a range subzone, representing the lower part of the Paracrochordiceras–Japonites Zone. At Deşli Caira, the latter is defined as the interval zone extending from the first occurrence (FO) of Stenopopanoceras (bed 822A2 Lower) to the last occurrence (LO) of Paracrochordiceras, presently identified in bed 2848.The S. transiens subzone is documented in the Caucasus and Iran. It can be correlated with New Zealand, whereas its occurrence in the Himalaya is uncertain. On a larger scale, the S. transiens subzone can be directly correlated with the ammonoid scale of Siberia (Arctic paleobioprovince), and precisely with the Karangatites arkhipovi subzone, first subzone of the lowermost Anisian Grambergia taymirensis Zone, on the basis of the FO of Stenopopanoceras. In Nevada (Pacific paleobioprovince), the FO of Stenopopanoceras is diachronous, being recorded in the Silberlingites mulleri zone (middle part of the lower Anisian), but the S. transiens subzone can be correlated with the lowermost Anisian Japonites welteri beds, on the basis of the FO of Paracrochordiceras. Based on the data currently available, the FOs of Stenopopanoceras and Paracrochordiceras appear to represent the most readily correlatable biostratigraphic events and are therefore considered the most suitable candidates for the selection of primary and secondary marker events for the Anisian GSSP.
The fishes from the Kupferschiefer (Zechstein, Upper Permian) of Germany are known for their exquisite preservation and they represent a window into fish life shortly before Earth’s most severe mass-extinction at the Permian–Triassic boundary where more than 90% of the marine life became extinct. Otoliths have been recorded in situ in the common Palaeoniscum freieslebeni but they have never been studied in detail. Here we describe otoliths in situ and as isolated finds of several early actinopterygians from the German Kupferschiefer as well as from the earliest neopterygian, Acentrophorus glaphyrus, and the coelacanthid Coelacanthus granulatus. We find that early actinopterygian otoliths shared a common morphological pattern characterized by a subtriangular outline and no clearly defined sulcus distinct from the otoliths of modern bony fishes. Furthermore, we are able to partly resolve the taxonomic identity of the collective early actinopterygian otolith form genus Archaeotolithus. Acentrophorus glaphyrus represents a completely different otolith morphology that shows certain resemblance to otoliths of the Halecomorphi. The morphological genesis of fish otoliths is discussed in the context of their evolution from the earliest finds in the Devonian to living taxa.
The Santa Isabel de Ranero (SIR) assemblage is one of the most significant collections of Ursus deningeri in the Iberian Peninsula. This study aims to characterise the formation processes of the site using a combined palaeobiological, geological and taphonomic approach. Fossil remains were recovered from four different sectors of the cave: Entrance and Esparta, which produced small surface collections, Bear, and Lion. The Bear Sector has provided evidence of, at least, 16 U. deningeri individuals and one lion dated to c. 300 ka (MIS 8). Two thirds of the bears are either late juveniles or early prime adults, and the sex of nine of these individuals has been determined: seven females and two males. Based on the presence of all anatomical parts, the absence of anthropogenic marks, and the low percentage of carnivore modifications, humans and hyaenas can be ruled out as the primary accumulating agents. Based on the demographic profile and the absence of shed deciduous dentition, we can also rule out the possibility that this accumulation is related to mortality during birthing or hibernation. We propose that this bear accumulation is the result of a natural endokarstic trap, probably originating from the upper conduit where the Esparta Sector is located. The Lion Sector yielded a limited assemblage from the Late Pleistocene, associated with allochthonous anorthic ferruginous nodules, which would suggest a natural trap directly connected to the exterior. The SIR assemblage highlights the important role of natural traps in reconstructing Pleistocene ecosystems in the Cantabrian region.
A new small tanystropheid archosauromorph is described from the Norian Dolomia di Forni Formation of the Friuli Venezia Giulia Autonomous Region, northeastern Italy. Despite the incompleteness of the only known skeleton, its anatomical articulation and the presence of a hyperelongated cervical vertebra connected to a string of non hyperelongated cervicals permit referral to a new taxon. The rest of the skeleton resembles that of Langobardisaurus pandolfii, previously reported from the Dolomia di Forni as well as from the Norian of Lombardy (northwestern Italy) and Tyrol (Austria), differing in the presence of at least nine cervicals; stouter mid-posterior cervicals with proportionally higher neural arch; shorter and posteriorly placed neural spine and zygapophyses not extending beyond the centrum; presence of “plowshare-like” ribs in the last two cervicals; presence of 14 trunk vertebrae including only three 'lumbars'; shape of the 'lumbar' ribs; radius proportionally shorter than the humerus; femur comparatively longer; more slender metatarsus; and proportions of the metatarsals with metatarsal III the longest. The new taxon differs from the long-necked Tanystropheus for having at least four mid-posterior cervicals that are not hyperelongated and two dorsals and one 'lumbar' more. It differs from the coeval Sclerostropheus fossai from Lombardy for lacking its diagnostic features. Unlike Tanytrachelos, the new taxon has “plowshare”-shaped cervical ribs only in the last two cervical vertebrae; mid-distal cervical vertebrae that are comparatively more elongated; one dorsal vertebra more; stouter dorsal vertebrae; gracile ribs in the 'lumbar' vertebrae; humerus less than twice the length of the radius and comparatively shorter; radius longer than ulna; more slender femur; and subequally long metatarsals I and II that are shorter than metatarsals III and IV (metatarsal III>IV>I>II).
Trends in the diversity, size, and complexity of Triassic foraminifera were studied. Diversity was calculated as the number of species and as standing diversity. Maximum linear dimensions were taken as approximations of size. As per complexity, foraminifera were graded based on test architecture and wall features. Foraminiferal diversity continually increased through the Triassic, but at a slower pace after the middle Anisian. The lower size limit of foraminifera does not change. The upper size limit and the mean size greatly increased in the early Anisian but remained constant afterward. The expansion of the size range suggests diversification into new niches and/or release from environmental pressure. The average size lies closer to the lower size limit, which suggests that small size is advantageous for some foraminifera, or that smaller species produce more evolutionary offspring. The most complex foraminifera in the Early Triassic – Anisian are multilocular. An exception is Kamurana chatalovi, which inherited a coarsely perforated wall from its Permian antecessors. New taxa with endoskeleton appeared during the Ladinian. Additional internal structures increase the strength of the test and may have allowed some lineages to expand into high-energy environments. During the Carnian, several miliolid genera with thick porcelaneous walls and coarse perforations appeared. In the Norian and Rhaetian, coarse perforations are also known in hyaline Involutina and Aulosina. Perforations could ease gas exchange or could be related to the acquisition of symbiotic algae in relation to the spreading of oligotrophic conditions and/or the evolution of suitable endosymbionts.
