A new genus is established for species of late Paleozoic pterioid bivalves that have substantial ontogenetic change in hinge characters during growth. Juvenile shells have small cardinal and posterior lateral teeth on the hinge that are overgrown on the adult shell and the hinge become edentulous. The shell has a wide ligament plate with a clinovincular ligament (new term). Adjacent to the cardinal teeth on juvenile shell, ligament sheets tend to have small, low amplitude folding and wavy alignment of ligament grooves. A new genus and species, Willipteria nestelli, is described and the species Leptodesma falcata Boyd and Newell, is transferred to genus Willipteria n. gen. Comparison of Willipteria n. gen. to Leptodesma reveals a need to revise Leptodesma. A study of the type lot of genotype species Leptodesma potens Hall, provides a redescription for the genus, presented here. Definition of the new term, clinovincular ligament, is presented. Discussion of muti-sheet ligaments is presented for duplivincular, monovincular, and clinovincular configurations.

http://zoobank.org/014f32de-414d-4cda-a5d4-790c35d0bfa5

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.

The Indo-West Pacific region serves as the primary habitat for the majority of extant hexapodid crabs. The hexapodids boast a rich evolutionary history dating back to the Cretaceous, marked by a significant radiation throughout the Cenozoic, while the Paleocene–Miocene of tropical America emerges as a pivotal center of radiation, evidenced by reported hexapodid species in Barbados, Panama, Peru, Trinidad, and Venezuela. Through an examination of the paleocarcinological collection at the Museu Paraense Emílio Goeldi, a new genus and species within Hexapodidae is described and illustrated. Rodneyellus feldmanni, the newly described taxon, is named in honor to Dr. Rodney Feldmann for his unwavering commitment to fossil crustacean research. This report marks the inaugural documentation of Hexapodidae in Brazil, encompassing both fossilized and extant representatives. Furthermore, the Pirabas Formation emerges as a critical locus for comprehending the contemporary distribution of decapod crustaceans across tropical America.

UUID: http://zoobank.org/9792bc1e-d06e-490b-a8e6-c23ee1c11fb1

Despite being a conspicuous group in many fossil-bearing beds from the Tepuel–Genoa Basin, the knowledge of bryozoans from Patagonia is scarce and outdated. The majority of bryozoan records are known from faunal components of the Lanipustula patagoniensis Biozone (Carboniferous, upper Serpukhovian–Moscovian), in lower to middle levels of the Pampa de Tepuel Formation, Tepuel Group. For the present contribution, we conducted a taxonomic study on bryozoan samples from the lower third of the Pampa de Tepuel Formation at the type section, Sierra de Tepuel, central-western Patagonia, Argentina. We found Paraptylopora gondwanica n. sp. along with species of Penniretepora, Polyporella, Septatopora, Levifenestella, Rectifenestella, Spinofenestella, and others still under study. Most studied fenestrate species are restricted to central-western Patagonia, indicating a degree of biogeographical isolation, while a few imply faunal migration between the western and eastern margins of southern Gondwana during the Late Paleozoic Ice Age. The bryozoan growth habits association and accompanying fauna suggests a mid-shelf to upper-slope environment characterized by deep, low-turbidity, euhaline waters and a soft to firm substrate.

UUID: http://zoobank.org/3bf56286-9fd7-43c2-b5f6-417e86994d08

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.

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

Scandentians, commonly known as treeshrews (tree shrews), are the sister group of primates and colugos within the Euarchonta, a clade with an evolutionary history rooted in the Cretaceous (Roberts et al., 2011; Melin et al., 2016). Scandentians are, however, extremely rare in the fossil record (Ni and Qiu, 2012; Li and Ni, 2016) and, other than the Oligocene species Ptilocercus kylin Li and Ni, 2016, their earliest undoubted representatives are not older than 18 Ma (Li and Ni, 2016, and references therein).

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.

UUID: http://zoobank.org/b3f862ca-3b4d-44c1-911c-820af4426029

The Cambrian edrioasteroid “Totiglobus” spencensis Wen et al., 2019 is redescribed on the basis of a new and exquisitely preserved specimen from the Cambrian Wuliuan of the Spence Shale Member, Langston Formation (Utah). This new occurrence is associated with soft-body preservation of several invertebrate groups and other shelly fossils. The description of “T.” spencensis was originally based on a single poorly preserved specimen. As a result, some of its features, such as curvature of the ambulacra and morphology of floor and cover plates, were misinterpreted or unavailable. The new material allows a new placement in Sprinkleoglobus spencensis n. comb. (Wen et al., 2019) on the basis of the general shape of the theca, attachment disc, and biserial flooring plates with podial pores and multiple cover plate series. The attachment disc of the new specimen lies in contact with a trilobite librigena, supporting evidence that this taxon is one of the earliest known examples of attachment to hard, mineralized substrata among Edrioasteroidea.

Dysnoetoporidae is a family of cheilostome bryozoans including only the genus Dysnoetopora Canu and Bassler, 1926, with three recognized species from the Late Cretaceous of the United States, Crimea, and Germany. The aim of this study was to record for the first time the presence of a fossil dysnoetoporid bryozoan in South America by describing Chenquepora miocenica new genus new species. This taxon was found in Miocene deposits of the Chenque Formation (early Langhian, ~15.37 Ma), on the Atlantic coast of Argentine Patagonia. Chenquepora n. gen. differs from Dysnoetopora in its encrusting colony and, consequently, in the absence of an endozone with long zooids arranged parallel to growth direction. This new record extends its paleobiogeographic distribution to the Southern Hemisphere and its stratigraphic range from the Campanian (Late Cretaceous) to the Miocene, showing that this extinct family survived the Cretaceous-Paleogene (K-Pg) mass-extinction event.

One of the challenges for bryozoans is to avoid refiltering water that has already had its plankton removed. Larger colonies develop colony-wide maculae-centered feeding currents to avoid refiltering water and generally have elevated maculae (monticules). We hypothesize that the height and density of spacing of monticules are inversely proportional to curvature of the colony surface. Larger, flatter colonies should have higher and more closely spaced monticules. We compare two Permian stenolaemate bryozoans whose colonies form branches with elliptical cross sections: the smaller and more elliptical cystoporate Evactinostella crucialis (Hudleston, 1883) from Western Australia (N = 17) and the larger and flatter trepostome Tabulipora sp. from eastern North Greenland (N = 15). Using calipers and digital elevation models, we measured curvature, monticule height, and number of monticules per area. Results indicate that Evactinostella branches are at least twice as curved as those of Tabulipora, their monticules are half the height of Tabulipora, and their monticules are 22% less densely spaced than those of Tabulipora. In Evactinostella colonies, surface curvature is inversely proportional to monticule height and spatial density, which is not true for Tabulipora. Therefore, we conclude that the smaller and more curved the colony surface, the less the colony needs robust colony-wide feeding currents created by tall, closely spaced monticules.

Insights into the paleoneurology and endocranial anatomy of ornithopod dinosaurs come largely from Northern Hemisphere taxa. The recently described non-hadrosaurid iguanodontian Fostoria dhimbangunmal from the Cenomanian of eastern Australia includes a partial skull that offers novel insights into its endocranial anatomy (i.e., the cavity housing the brain). Here, we describe the paleoneurology of F. dhimbangunmal based on a digital cranial endocast obtained from computed tomography. The endocast is mostly complete; however, it is diagenetically dorsoventrally compressed and its ventral limits are not preserved. The endocranial anatomy of F. dhimbangunmal is generally consistent with that of other non-hadrosaurid iguanodontians, including a well-developed olfactory apparatus, suggesting a good sense of smell. In contrast to hadrosaurids and some non-hadrosaurid iguanodontians, F. dhimbangunmal possesses the ancestral flexure condition, in which cranial and pontine flexure angles are subequal. The cerebrum makes up a significant portion of the endocast volume; however, the cerebral hemispheres are not as enlarged or bulbous as seen in hadrosaurids. The forebrain of F. dhimbangunmal did not fill the braincase to the same extent as in hadrosaurids. A distinct vacuity in the supraoccipital of F. dhimbangunmal may represent a new autapomorphy. This study provides the first insights into the neuroanatomy of an Australian iguanodontian dinosaur.

Jurassic cyrtocrinids from Spain are first documented here as representing relatively diverse assemblages from the western Tethys. The species Ascidicrinus pentagonus, Eugeniacrinites cariophilites, Gammarocrinites compressus, Pilocrinus moussoni, Sclerocrinus cf. S. strambergensis, and Tetracrinus moniliformis are described from Oxfordian marl levels belonging to the Yátova Formation, around Tosos (Zaragoza, NE Spain). Although based on partially disarticulated material, these fossils preserve cups, stem columnals, attachment structures, and brachial plates. Based on the sedimentology and associated invertebrate fauna, cyrtocrinids from this area lived below storm wave action but eventually were affected by storms, as opposed to their modern counterparts that occupy deep water environments. Some specimens preserve traces of interactions with other organisms, such as predation marks or epibiontic colonization during life and post-mortem. Attachment structures suggest cyrtocrinids mostly attached on sponges. We note that diversity of cyrtocrinids changed in step with the abundance of sponge reefs in the Jurassic, suggesting that both groups probably had an important link in that period related with similar ecological requirements.

Haliotis Linnaeus, 1758, a commercially important gastropod, is the only known genus in the family Haliotidae (Mollusca, Vetigastropoda, or abalone) worldwide. Its poor Cenozoic record and high intraspecific variability resulted in different interpretations of nomenclature, impeding a robust species-level taxonomy and biogeographic history. Among the best-studied forms, three subspecies of H. tuberculata Linnaeus, 1758 currently inhabit the temperate waters of the Mediterranean and the eastern Atlantic. New findings in the Pliocene of Tuscany (Italy) are presented here, and the taxonomy of the European record is revised. On the basis of a multivariate analysis of shell morphometrics for the first time applied to the study of fossil abalones, and consistent with the chronostratigraphic and geographic framework, H. plioetrusca n. sp. is introduced and H. volhynica Eichwald, 1829 and H. lamellosoides Sacco, 1897 are reinstated as valid species. Some recently described forms from the Pliocene of Spain are placed in synonymy with H. lamellosoides. Haliotis ovata Michelotti, 1847 is proposed as the ancestral taxon of modern H. tuberculata, via H. lamellosoides. This lineage diversified in the subtropical/warm temperate Pliocene Mediterranean, represented by H. lamellosoides, H. bertinii Forli et al., 2003 and H. plioetrusca. The progressive global cooling starting at around 3.0 Ma is associated with the appearance of H. tuberculata at temperate latitudes. H. plioetrusca is not known from younger strata, whereas H. bertinii survived into the Calabrian.

UUID: http://zoobank.org/7c2f2258-2574-4976-a2f5-804c54c86679

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.

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

Obruchevodid petalodonts are rare small chondrichthyans known from nearly complete to partial skeletons from the Upper Mississippian (Serpukhovian) Bear Gulch Limestone of central Montana and isolated teeth from the Upper Mississippian Bangor Limestone of northern Alabama. New records of obruchevodid petalodonts are presented here from the Middle Mississippian (Viséan) Joppa Member of the Ste. Genevieve Formation at Mammoth Cave National Park, Kentucky. Obruchevodids are here represented by multiple teeth of a new taxon, Clavusodens mcginnisi n. gen. n. sp., and a single tooth referred to ?Netsepoye sp. Clavusodens mcginnisi n. gen. n. sp. is characterized by teeth with pointed mesiodistal and lingual margins and more robust chisel-like cusps on the anterolateral and distolateral teeth. The suggestion that obruchevodid petalodonts evolved to inhabit complex reef-like environments and other nearshore habitats with a feeding ecology analogous to extant triggerfish is explored and discussed.

UUID: http://zoobank.org/0955c37a-c458-4a4d-89c4-01d6915adeca

Rare specimens of eldonioids recovered from the lower Cambrian (Series 2, Stage 4) Emu Bay Shale (EBS) Konservat-Lagerstätte represent the first record of the group for the Cambrian of East Gondwana. The disc-shaped body of the EBS taxon bears fine concentric corrugations on the dorsal surface and, ventrally, a series of internal lobes that have primary and secondary bifurcations, as well as a coiled sac. It appears to be most similar to Rotadiscus and Pararotadiscus of the Cambrian Chengjiang and Kaili biotas of South China, respectively. While the structure of the internal lobes would indicate that this occurrence in the EBS represents a new taxon within the Rotadiscidae, lack of detail regarding the precise number of internal lobes and the condition of the circumoral tentacles warrants a more conservative approach in leaving the genus and species under open nomenclature. The EBS specimens also host trace fossils, including the remains of a burrow, which are generally lacking in the body-fossil-bearing layers of the Konservat-Lagerstätte interval. These traces appear to have been made by small organisms and are similar to traces associated with the discs of Pararotadiscus guizhouensis Zhao and Zhu, 1994 from the Kaili Biota. The available taphonomic, paleoenvironmental, and ichnological evidence indicates that the EBS eldonioids are most likely vagrants that were transported or settled into the ‘preservational trap’ and subsequently exposed on the substrate for a brief period before burial, thereby allowing organisms to exploit their carcasses for nutrients or other purposes.