The knowledge on decapod crustaceans considerably increased in recent years, including that of the glypheid lobsters, known from the Early Jurassic to the present. On the basis of known occurrences worldwide, we analyze the spatial and temporal distribution of 86 species of the family Glypheidae and provide a general description of their history since the Early Jurassic. The first records are from low- to mid-paleolatitude localities of central Europe, around the margins of northern Tethys. During the Early Jurassic they diversified fast, and by Pliensbachian/Toarcian times they already had a wide paleolatitudinal range in both hemispheres. After a short decline in late Toarcian–Aalenian, they reached the highest diversity of their history during Oxfordian times and can be regarded as Jurassic cosmopolitans. After a diversity decline and occurrence gap during the earliest Cretaceous, they recovered again in the Barremian, but they were clearly beginning to be less diverse than before in the Tethys, to the point that by the Campanian their known occurrences were confined to high paleolatitudes. They survived the Cretaceous/Paleogene crisis but in Paleocene and Eocene times remained restricted to cold waters, being seemingly absent from low paleolatitudes. For a long time, the group was thought to be extinct about 50 million years ago, until two extant species were discovered in the deep Pacific. We also add to the knowledge of the only South American Jurassic Glypheidae known so far, the Toarcian Paraglyphea eureka (Damborenea and Manceñido, 1987) on the basis of newly collected material, discussing its significance and taphonomy.

The Paragaricocrinidae is an enigmatic late Paleozoic family of camerate crinoids that retained a robustly constructed calyx more typical of Devonian to Early Mississippian crinoids. The discovery of the oldest member of this family, Tuscumbiacrinus madisonensis n. gen. n. sp., initiated a phylogenetic investigation of the Paragaricocrinidae and consideration of its diversification and paleobiogeographic distribution. Phylogenetic analyses demonstrate the need to describe Tuscumbiacrinus n. gen and conduct revisions to preexisting taxa, resulting in the description of Palenciacrinus mudaensis n. gen. n. sp.; Pulcheracrinus n. gen.; Nipponicrinus hashimotoi n. gen. n. sp.; and Nipponicrinus akiyoshiensis n. gen. n. sp. Megaliocrinus exotericus Strimple is reassigned to Pulcheracrinus n. gen. In addition to having an anachronistic morphology, relatively few specimens are known through the ca. 76-million-year duration of this family. This pattern is unlikely to have resulted from low fossil sampling alone, and instead likely reflects low abundance and/or taxonomic richness of a long-lived waning clade. From its apparent origination in Laurussia during the Mississippian, the Paragaricocrinidae diversified into a cosmopolitan clade. Following a diversity drop during the Pennsylvanian, the Paragaricocrinidae persisted but exemplified characteristics of a dead clade walking until its eventual extinction during the middle Permian (Wordian).

http://zoobank.org/3e5df71c-112f-4556-96c5-a5a62d4a4da9

Gnathodus pseudosemiglaber is an important conodont species for Lower Mississippian biostratigraphy, but differentiating it from morphologically similar species remains difficult due to uncertainties in the intraspecific, ontogenetic, and phylogenetic relationships between taxa. To clarify these uncertainties, a fauna from the Yudong Formation at the Yudong II section in Baoshan, southwestern China, that contains abundant G. pseudosemiglaber was analyzed using population thinking. Quantitative morphometric methods were employed to analyze G. pseudosemiglaber specimens. Six anatomical measurements were taken on specimens of different ontogenetic stages to conduct analyses on normal distribution, correlation, and regression. A geometric morphometric analysis based on 13 landmarks was also performed. The results demonstrated that all analyzed specimens belonged to a single population. The dorsal carina of G. pseudosemiglaber has a growth rate that far exceeds other features on the platform through ontogeny as well as exhibits a series of transverse ridges in adult individuals, which becomes the most prominent diagnostic characteristic of this species. Thus, an amended systematic description for G. pseudosemiglaber is presented. Gnathodus girtyi maxwelli, a previously named species, however, is regarded as a junior synonym of G. pseudosemiglaber. Based on the revised taxonomy of G. pseudosemiglaber, its possible phylogenetic lineages and biostratigraphic use were reviewed. The ancestor of G. pseudosemiglaber is probably G. semiglaber but its descendant is unknown. The range of G. pseudosemiglaber is from the Scaliognathus anchoralis–Doliognathus latus Zone of uppermost Tournaisian to the lower part of the G. bilineatus Zone of middle-upper Visean.

Xandarellida is a clade of artiopodan euarthropods known exclusively from the early Cambrian (Series 2, Stage 3) Chengjiang biota of South China, apart from the possible inclusion of Phytophilaspis Ivantsov, 1999 from the early Cambrian Sinsk Biota of Siberia. A rare euarthropod taxon represented by four specimens from the Emu Bay Shale (Cambrian Series 2, Stage 4) of Kangaroo Island, South Australia, represents the first record of Xandarellida from East Gondwana. A new monotypic genus, Austroxandarella n. gen., is based on A. poikar n. sp., being most readily distinguished by its elongate pygidium. Close affinities to Xandarella Hou et al., 1991 are suggested by a thorax of 10 tergites, with progressive elongation of the posterior three tergites relative to the seven anterior tergites of subequal length—this elongation representing the dorsoventral decoupling of biramous appendage pairs and tergites shared by all xandarellids. Discovery of an Australian xandarellid adds more support for biogeographic affinities between East Gondwana and South China in the early Cambrian.

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This is the first report of Jurassic brachyurans and anomurans from the territory of Russia. These findings come from the Upper Jurassic (Oxfordian) reef limestones of the North Caucasus. The anomuran Gastrosacus wetzleri von Meyer, 1851 was collected from the locality near the Urup River and is the first find of this species outside of western Europe. The dromiacean crab, Goniodromites aliquantulus Schweitzer, Feldmann, and Lazăr, 2007, was discovered from another locality near the Kamennomostsky village. This species was first described from the Oxfordian of Romania. Findings of fossil remains of Goniodromites aliquantulus and Gastrosacus wetzleri from the Oxfordian of the North Caucasus indicate an interconnected paleobiogeographical community of decapod faunas in the Late Jurassic in the Tethys basins.

Eocene snakes of India have the potential to shed light on the nature of snake diversification on the subcontinent following the Deccan volcanism at the Cretaceous-Paleogene boundary (K-Pg), when India was still a northward-drifting isolated landmass prior to its collision with Asia. Here, we report a diverse snake fauna from the Eocene of Kutch, western India. The fauna, dominated by aquatic forms, includes palaeophiids, a giant madtsoiid, and a possible nigerophiid. The palaeophiids from the middle Eocene (late Lutetian) comprise ?Palaeophis Owen, 1841 and Pterosphenus rannensis n. sp. Together, these taxa enrich the record of fossil snakes in the poorly known late Lutetian of India and represent the youngest record of Palaeophiidae from the Indian subcontinent. Pterosphenus rannensis n. sp. shows intermediate morphology between Palaeophis and Pterosphenus-grade snakes and is phylogenetically the earliest-diverging member of Pterosphenus Lucas, 1898. Additionally, the middle Eocene Pterosphenus biswasi Rage et al., 2003 is reassessed and retained as a valid taxon based on pterapophyseal morphology and overall form. Biogeographic considerations highlight the importance of the Indian fossil record in understanding the origin and diversification of the genus Pterosphenus. The prevalence of niche partitioning is suggested for the palaeophiids, with Pterosphenus rannensis n. sp. recovered from a tidal setting and ?Palaeophis sp. indet. from a marsh/swamp setting. The new Indian madtsoiid from the middle Eocene (early Lutetian) represents a sympatric taxon with the terrestrial/semiaquatic giant Vasuki indicus Datta and Bajpai, 2024 coexisting in a back-swamp marsh setting. The early Eocene (Ypresian) nigerophiid is among the oldest Cenozoic occurrences of this family globally.

UUID: http://zoobank.org/dc529074-73a6-4869-9b49-44caf9e2d956

Mecochirid lobsters (Glypheidea, Mecochiridae) are iconic decapod crustaceans from the Jurassic and Cretaceous. The composition of the family in terms of included genera strongly fluctuated during the twentieth century because of the lack of study of the type specimens, which are herein illustrated. On the basis of the type material of different species housed in German, French, British, and Romanian museums and universities, Eumorphia von Meyer, 1847 (type species Carcinium sociale von Meyer, 1841) is re-established as a valid mecochirid genus. Six species are considered, including the new species Eumorphia fabianmuelleri (Callovian, Germany), and the synonymization of Romaniacheiros Franţescu et al., 2018 with Eumorphia is proposed. The composition of the revised family Mecochiridae is discussed.

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Abrupt appearance of the dikelocephalid trilobite genus Osceolia in later Cambrian strata of the upper Mississippi Valley immediately above a flooding surface is succeeded by widespread regional occurrence among approximately eight parasequences in the early part of a falling stage systems tract. All of Osceolia’s sclerite types are illustrated for the first time. The taxonomy is revised to recognize two species, of which O. tumerispina is new and known only from a dolomitic horizon at a single locality. All five of Ulrich and Resser’s (1930) Osceolia species are synonymized within O. osceola (Hall, 1863), a species widespread in regional dolomitic mudstones and feldspathic sandstones. Osceolia osceola shows notable polymorphism in the presence of an axial ledge in the anterior cranidial border. Holaspid ontogenetic variation evident within bedding-plane collections of O. osceola scales with that occurring among collections and across facies. Collection-related morphological differences among the samples beyond those related to size are subtle. The occurrence of larger individuals in more distal settings may reflect ontogenetically related habitat preference. Osceolinae Ulrich and Resser, 1930 is rejected. The closest relatives of the two Osceolia species may occur outside of the upper Mississippi Valley. Material of a local, stratigraphically older, and possibly related Ulrich and Resser 1930 nomen nudum is figured and described for the first time. Osceolia’s cranidial morphotype was converged upon several times during the evolution of Cambrian trilobites among relatives both phylogenetically close and distant.

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The first unequivocal fossil of a tupinambine in North America is described on the basis of a single thoracic vertebra from a middle Miocene (Barstovian 2) paleocoastal deposit in southwestern Georgia, USA. Wautaugategu formidus n. gen. n. sp. is a mid- to large-bodied taxon with a unique mosaic of tupinambine features. Vertebral position of the fossil was determined both by qualitative and quantitative methods. This record is coeval with the warmest part of the Neogene, the Middle Miocene Climatic Optimum, when increased temperatures would have made the southeastern United Sates more habitable for this hyperthermic group of lizards. Although the arrival time of tupinambines into North America is still unclear, an increasing number of endemic South American reptiles, including the large-bodied iguanid Ctenosaura, dispersed as far North as Panama by the early Miocene before formation of the Panamanian Isthmus.

http://zoobank.org/58ded940-9082-46ae-8023-4b5f1b01691e

Squamate faunas from the lower Eocene of Europe are rare. We here describe pleurodontan iguanian (potentially Geiseltaliellus Kuhn, 1944), scincoid, and Squamata indet. jaw remains from Cos locality (near the Caylus village, southwestern France). The age of the Cos deposit has been proposed to fit the MP 10−11 interval (MP 10b; late Ypresian). Thus, it either corresponds to the end of the Early Eocene Climatic Optimum (EECO) or slightly postdates it. Although very fragmentary, the finds represent the first evidence of these clades in this locality, which is one of the oldest from Phosphorites du Quercy, adding to the squamate paleobiodiversity of the site. Besides iguanians and scincoids, the fauna also includes gekkotans, glyptosaurids, varanoids, and a constrictor snake. Some of the genera from Cos are known solely from this locality, revealing a crucial part of the squamate history in Europe. In the last few years, our knowledge of the Paleocene and especially early Eocene lizard faunas has increased. This allows a better understanding of the faunas and their changes due to temperature changes and migrations. Records are still very sketchy at European localities, but the overall picture is somewhat clearer, even on a smaller scale. A small but visible drop in lizard diversity appears to be present at localities from MP 8−9 relative to those from MP 7, whereas at MP 10, the diversity slightly increased. This appears to correlate well with observed changes in temperature.

New, well-preserved specimens of the paracrinoids Wellerocystis and Implicaticystis provide new morphological data. All specimens originate from reef facies in the Kimmswick Limestone (Upper Ordovician, Sandbian–Katian) at a single locality near St Louis, Missouri, USA. Wellerocystis is characterized by an ovoid theca largely composed of imperforate plates arranged in vertical columns lacking pore-structures but with fine granular sculpture; four recumbent branched uniserial ambulacra with up to seven branches in total; a mouth frame of four plates, one of which also contributes to the periproct frame; a sinuous hydropore; and circular gonopore. The stem is unknown; its facet is small and circular, similar to that of Platycystites. Implicaticystis is characterized by a circular, heteromorphic stem, ovoid theca composed of externally concave, perforate plates with foerstepores, internal pararhombs, and a mouth frame of three plates plus two lateral plates each bearing two facets for erect, uniserial, hemipinnate pseudoarms. Foerstepores connect to tubes that pass through the theca near plate sutures. Internal lamellae of pararhombs support thecal plates much as A-frames support ridged rooves. Erect versus recumbent and branched ambulacra evolved repeatedly in pelmatozoans so both are less useful in classifying paracrinoids than presence or absence of unique pore-structures. The sister group of paracrinoids could have included Columbocystis, rhipidocystids, and cryptocrinitids. Columbocystis is commonly mentioned in discussions in this context, but its asymmetrical facets suggest it had biserial feeding appendages, unlike uniserial paracrinoid appendages.

This paper describes three collections of vertebrate fossils from the Lower Cretaceous Newark Canyon Formation of Eureka County, Nevada, made by the United States Geological Survey in 1961. Briefly mentioned in the prior literature, these specimens have gone unstudied for more than sixty years, until their recent transfer to the Smithsonian Institution. Re-examination of the materials reveals the first records of neoceratopsian and tyrannosauroid dinosaurs in the Newark Canyon Formation. In addition to augmenting the known vertebrate fauna from this poorly studied stratum, these occurrences provide important new data on otherwise rare taxa during a time of major faunal transition in North America.

A new pylochelid hermit crab, Cretatrizocheles rodfeldmanni new species, is recorded from a Lower Cretaceous (Aptian/Albian) olistolith reefal limestone block near the village of Velika Strmica, southeast Slovenia. It adds to the fossil record of the symmetrical pagurid subfamily Trizochelinae, whose members appear to have been successful inhabitants of shallow-marine reefal settings during at the least the Late Jurassic and Early Cretaceous across Europe. Given their exclusive occurrence in shallow-marine, reef-related facies of Mesozoic age and the present-day confinement to deep-marine settings, trizocheline paguroids may also illustrate the effect of the Mesozoic Marine Revolution.

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The presence of a basal cingulum, fluting, and overall size have been used to differentiate nodosaurid and ankylosaurid teeth for decades. The taxonomic utility of tooth morphology in ankylosaurs, however, has not been quantitatively tested. In addition, new phylogenetic hypotheses recognize four ankylosaur families (Panoplosauridae, Polacanthidae, Struthiosauridae, and Ankylosauridae), rather than the traditional nodosaurid–ankylosaurid dichotomy. Understanding ankylosaur tooth variation could better help identify taxa with ambiguous phylogenetic affinities or allow isolated teeth to test paleoecological questions such as a potential extirpation of mid-Cretaceous ankylosaurids from Laramidia. We analyzed a large sample of ankylosaur teeth using traditional and geometric morphometrics and investigated the utility of size and the presence of a cingulum and fluting for differentiating ankylosaur teeth. Morphometric analyses show that “nodosaurids” had the greatest variation in tooth shape and size. Panoplosauridae and Struthiosauridae account for a large amount of “nodosaurid” variation, whereas basal ankylosaurs, Polacanthidae, and Ankylosauridae share a similar restricted morphospace. Teeth with a crown base length or height over 10 mm are found only in panoplosaurids, struthiosaurids, and Peloroplites, but smaller sizes are found in all clades. A basal cingulum and fluting are associated with Ankylosauridae and Panoplosauridae. Linear discriminant analyses could accurately identify only between 50% and 75% of the teeth in our sample; thus, they should be used in conjunction with size and discrete traits when identifying isolated teeth. With these findings, caution should be used when attempting to use isolated ankylosaur teeth in broader paleoecological questions, and reclassification of museum collections should be undertaken.

Numerous fish microremains, including diverse chondrichthyans, have been recovered for the first time in the Carboniferous–lower Permian of the Naqing, Narao, and Shanglong deep-water sections from Guizhou Province, South China, as well as in the Serpukhovian–lower Bashkirian of the Sholaksay section from Kazakhstan. The richest assemblage was found in the Bashkirian strata of the three South China sections. These findings are the first reliable record of Pennsylvanian fishes in China. The fish assemblage from the Sholaksay section and the Bashkirian of China closely resemble those from the same interval in the Aksu section, Uzbekistan. All studied fish faunas from these three Asian regions are associated with the Paleotethys. Notably, while Bashkirian chondrichthyan faunas generally exhibit low taxonomical diversity in many regions of the world, the deep-water fish assemblages from South China, Kazakhstan, and Uzbekistan are characterized by high taxonomical diversity. The fish fauna includes widely distributed chondrichthyan taxa; however, Gissarodus occurs only in these three Asian regions.

The James Ross Basin, situated in the northwestern portion of the Antarctic Peninsula, holds one of the most complete sedimentary records of the Cretaceous, and hosts exceptionally well-preserved and diverse fossil assemblages, particularly notable for high southern latitudes. The Santa Marta Formation (Santonian–Campanian) harbors a rich decapod crustacean fauna, including Anomura, Astacidea, Achelata, Brachyura, and Glypheidea. Among brachyuran crabs, only four families have been described on James Ross Island: Homolodromiidae, Necrocarcinidae, Prosopidae, and Raninidae. This work focuses on a brachyuran from the Marambio Group, a part of the Santa Marta Formation. The material presented here was collected during the 41st Brazilian Antarctic Operation by researchers of the PALEOANTAR project. The site consists of a sequence of intercalated volcanic sandstones, siltstones, and tuffs, interpreted as a set of volcanoclastic deposits formed in a deltaic environment. The specimen described here with a well-preserved ventral surface, Sabellidromites santamarta new species, is assigned to the Dynomenidae based on uropods as calcified dorsal plates, a reduced, obliquely subdorsal fifth pereopod (fourth pereopod not reduced), and characteristics of the dorsal carapace. The occurrence of Sabellidromites santamarta n. sp. in the Santonian–Campanian of Antarctica suggests biogeographic exchanges of the dynomenid fauna between the Northern and Southern hemispheres during the Late Cretaceous.

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The Caribbean islands represent some of the most biologically diverse places on Earth, but much of that diversity is now at risk due to human impact. Larger islands in the Caribbean host more native species, but small islands still hold together a significant portion of the regional biota. Although our knowledge of extinct and extirpated taxa continues to improve, there are hundreds of islands, each with their own unique faunal histories from where there is little information about their ancient diversity. Sombrero is a very small island (0.38 km2) located within the limits between the Greater and Lesser Antilles and is largely barren of vegetation and freshwater. The island was extensively mined for bird guano in the 1800s, which profoundly altered its topography and fauna. Here, we describe a collection of microvertebrates recovered in 1964 from Sombrero, which documents an unexpectedly high number of colonization events and high extinction rate for this territory. The late Quaternary deposits from the island contain remains of five types of lizards, a snake, a tortoise, and an anuran that colonized the island once it became aerially exposed in the early Pleistocene. The ability for such a small, remote island to have eight colonizing taxa in < 2.5 Ma, provides support for the role that island hopping played in regional biodiversity in the Cenozoic (e.g., GAARlandia), even across small, barren islands. Furthermore, these fossils further show that large scale defaunation also affected vertebrate communities on very small islands in the Caribbean.

The allosauroid theropod dinosaurs of the clade Carcharodontosauridae were the apex predators in terrestrial ecosystems of the Early Cretaceous but were replaced in this ecological niche by Tyrannnosauridae in the Late Cretaceous. Details of this turnover are poorly known because only two transitional ecosystems, containing both carcharodontosaurids and tyrannosauroids, had been recognized to date (Cenomanian Cedar Mountain Formation of Utah, USA, and Turonian Bissekty Formation of Uzbekistan). Moreover, the presence of carcharodontosaurids in the Bissekty Formation, based on a maxilla fragment identified as Ulughbegsaurus uzbekistanensis Tanaka et al., 2021, has been recently questioned. Here we report on the third ecosystem containing both clades of apex predators, the Cenomanian Khodzhakul Formation in Uzbekistan. This new occurrence of Carcharodontosauridae is based on a newly identified maxilla that closely resembles the holotype maxilla of U. uzbekistanensis and is identified as Ulughbegsaurus sp. The revised morphological characters of both specimens support attribution of Ulughbegsaurus to Carcharodontosauridae. We report a novel neurovascular feature of the theropod maxilla—a medial alveolar canal that supplied the alveoli medially and contained tributaries of the palatine vessels in Ulughbegsaurus.

Despite the lesser preservation of bat fossils compared to karstic sites, fluviolacustrine deposits are of crucial importance for assessing the local palaeodiversity of bats. This was confirmed by three faunas from the upper Miocene of Slovakia (Borský Svätý Jur, MN9; Studienka A, MN9; Krásno, MN11), which comprise seven species—Miostrellus cf. Miostrellus noctuloides (Lartet, 1851), Myotis cf. Myotis murinoides (Lartet, 1851), ‘Otonycteris’ sp. indet., Miniopterus sp. indet., Vespertilionidae gen. indet. sp. indet. 1, Vespertilionidae gen. indet. sp. indet. 2, and Rhinolophus cf. Rhinolophus grivensis Depéret, 1892. Bats represent ~ 1.40% of the small mammal remains from Borský Svätý Jur, ~ 0.25% of those from Studienka A, and ~ 1.78% of those from Krásno. The MN11 fauna from Krásno consists of six distinct species, which is unusual for a Miocene fluviolacustrine deposit. Most likely, this is the consequence of the relatively high frequency of bats in the taphocoenosis, therefore providing a more complete and more accurate picture of the Carpathian late Miocene bat faunas. This material encourages the study of fluviolacustrine deposits to unravel the cryptic diversity of Neogene taxa.

Differences in brachyuran morphology among and between juveniles and adults as well as sexual dimorphism are not well studied among extinct brachyuran crabs. Carapace dimorphism and morphological changes during growth have received little attention in fossil crabs. Tetracarcinus subquadratus Weller, 1905, Dakoticancer australis Rathbun, 1935, and Seorsus wadei Bishop, 1988 are herein synonymized on the basis of examination of dozens to hundreds of specimens of each from the same locality. Synoriacarcinus new genus is named to embrace two species previously referred to Seorsus Bishop, 1988, Synoriacarcinus millerae (Bishop, 1992), new combination, and Synoriacarcinus kauffmani (Feldmann et al., 2013), new combination. Both Dakoticancridae and Ibericancridae were well established on coastal North America during the Late Cretaceous but became extinct in the end-Cretaceous event.

UUID: http://zoobank.org/2eab7247-6235-435d-8eb1-b40d5a633e2b