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A large, edrioasteroid-bearing hardground surface from the base of the Bellevue Member of the Grant Lake Formation near Maysville, Mason County, Kentucky is described. Four species are represented including Streptaster vorticellatus (Hall), Carneyella ulrichi Bassler and Shideler, Carneyella pilea (Hall), and Curvitriordo stecki n. sp. Specimens of S. vorticellatus and C. pilea add little to the known morphologies of these species. However, prior to this study C. ulrichi was known from the unique holotype, and Curvitriordo stecki n. sp. adds greatly to out understanding of Curvitriordo which was previously known from two species comprising three poorly preserved specimens. Curvitriordo stecki shows a bimodal size frequency distribution suggesting seasonal breeding whereas Carneyella ulrichi shows a left skewed size frequency suggesting low juvenile mortality. Streptaster vorticellatus shows a tight unimodal size frequency distribution suggestive of a single spat fall accumulation.
A phylogenetic analysis and review of Paleozoic phyllocarid systematics is presented using morphology-based characters from Cambrian to modern taxa. The resulting cladograms of the Phyllocarida suggest that the suborder Ceratiocaridina as traditionally defined (families Ceratiocarididae and Caryocarididae) is paraphyletic. Caryocarididae is subsequently elevated to subordinal rank with the erection of Caryocaridina n. suborder, resulting in two monophyletic suborders. Haplocaris n. gen. is erected to contain Caryocarididae taxa without triangular spine-like projections of the anterior telson margin. Emended diagnoses, quantified with morphometrics where appropriate, are integrated into this analysis, and result in synonymy of many Cambrian—Silurian caryocaridids and ceratiocaridids with pre-existing taxa. Two representatives of the Leptostraca are included in this analysis. A visual key of well-established representatives of the Ceratiocaridina is presented and suggestions are offered that will help to improve the long-term stability of the Archaeostraca.
New and old species and genera of the family Guadalupiidae (spherulitic hypercalcified demosponges of the order Agelasida) are described or redescribed from the West Texas Permian. The entire family is reviewed and observations are made on the epibionts, growth patterns, functional morphology, ecological relationships, morphologic variability, modular structure, and evolutionary history of these largely reef-dwelling sponges. The stratigraphic distribution of species is also noted; many are limited and can define zones. The new genera Exovasa and Incisimura and the new species Guadalupia auricula, G. cupulosa, G. ramescens, G. microcamera, G. vasa, Cystothalamia megacysta, Lemonea simplex, Incisimura bella, and Exovasa cystauletoides are described. Almost all previously published taxa are redescribed and in some cases redefined. The Guadalupiidae are unique among hypercalcified sponges in having a modular thalamid layer (thalamidarium) covered on the exhalant surface by a non-modular stromatoporoid-like layer (trabecularium).
The enigmatic fossil Moniopterus japonicusHatai et al., 1974 from the early Middle Miocene Moniwa Formation of northern Japan has been described as the only known example of fossil sea-snake eggs and also as fossilized pupal chambers of a coleopteran insect. A reexamination of the holotype provides no evidence in support of these previous interpretations. Scanning electronic microscopy and computed tomography observations on the holotype reveal that the calcareous lining, previously interpreted as eggshell, is instead composed of irregular spherulitic prisms, thin in the middle and becoming thicker toward both ends. In addition to the elongate oval shape and the presence of an opening at the more pointed end, these observations strongly suggest that M. japonicus is a boring of the mytilid boring bivalve Lithophaga isolated from the host rock. This reinterpretation is further supported by the occurrence of similar isolated and in situ borings with Lithophaga shells within the type and a nearby locality. Regarding this fossil as an ichnofossil makes the generic name Moniopterus a junior synonym of GastrochaenolitesLeymerie, 1842 and the species name japonicus is a senior synonym of Gastrochaenolites torpedoKelly and Bromley, 1984. G. torpedo should thus be replaced with Gastrochaenolites japonicus (Hatai et al., 1974).
The order Litopterna is represented in the São José de Itaboraí basin by four species belonging to the families Protolipternidae (Protolipterna ellipsodontoides, Miguelsoria parayirunhor and Asmithwoodwardia scotti) and Proterotheriidae (Paranisolambda prodromus). Only the deciduous teeth of P. prodromus are known so far. Isolated milk premolars are described for P. ellipsodontoides and M. parayirunhor. The known specimens assigned to P. prodromus are redescribed. No milk teeth are known for A. scotti. The upper and lower milk teeth of Protolipternidae, especially dP3, are more molarized than their successors, resembling, in several features later Proterotheriidae. They provide new support for the placement of this family within the order Litopterna. The analysis of the wear level of dp2–4/dP2–4 and X-ray images of the lower jaw of P. prodromus suggests that the second teeth of the premolar series, in upper and lower jaw, are retained milk premolars. Some information on tooth replacement pattern of P. ellipsodontoides and P. prodromus are also provided.
A primitive paromomyid plesiadapiform primate, Edworthia lerbekmoi new genus and species, is described from a recently discovered locality in the Paskapoo Formation, exposed at a road cut in Edworthy Municipal Park, Bow River Valley, Calgary, Alberta, Canada. The new taxon, probably middle Torrejonian (To2) in age, is based on two dentary fragments containing well-preserved dentitions that bracket p2–4, m1–3. With the exception of the basal Paromomys, E. lerbekmoi differs from all other paromomyids in retaining p2, but p2 in the new paromomyid is single-rooted, not two-rooted as in Paromomys. E. lerbekmoi differs further from Paromomys in having an enlarged anterior alveolus for a tooth immediately anterior to p2, hypothesized to be i1. Unlike other paromomyids with an enlarged i1, however, this tooth in E. lerbekmoi was obliquely, not horizontally, oriented and its alveolus opens dorsally, in the alveolar row, not anteriorly, as in other paromomyids in which i1 is greatly enlarged. This suggests that E. lerbekmoi represents a previously unknown paromomyid lineage that evolved from an ancestor having obliquely oriented lower incisors as in the basal primate Purgatorius, not from an ancestor in which i1 was already subhorizontal in orientation, as in Paromomys. If this working hypothesis is correct or whether in the future some other evolutionary scenario will better account for the unique anterior dentition in E. lerbekmoi, the new paromomyid nonetheless demonstrates that crucial aspects of the earliest history of the important plesiadapiform family Paromomyidae remain to be discovered.
A well-preserved highly diverse radiolarian fauna was discovered from the Upper Permian Dalong Formation in Guangxi, South China. A new genus and 19 species are described in this paper. Zhuangodiscus n. gen. belongs to the Family Relindellidae Kozur and Möstler. The 19 species include eight new species (Albaillella bialata, Neoalbaillella camarata, Neoalbaillella cephalota, Zhuangodiscus biacanthus, Zhuangodiscus orthacanthus, Zhuangodiscus pentacanthus, Tetratormentum nandanensis, Octatormentum yaoi) and 11 undetermined species. A new radiolarian assemblage, Neoalbaillella camarata Assemblage is proposed, which is located at the upper part of Neoalbaillella optima Assemblage Zone, corresponds well with the Albaillella yaoi Zone.
The Late Cretaceous to late Paleocene record of glycymeridid bivalves in the region extending from the Alaska Peninsula, southward to Baja California, Mexico is studied in detail for the first time. Glycymeris pacifica (Anderson, 1902), of late Cenomanian to late Turonian age, is the earliest known glycymeridid in the study area. Very locally, it is found with the middle to late Turonian Glycymeris yoloensis n. sp. The latter apparently represents some intermediate state between genus Glycymerisda Costa, 1778 and genus GlycymeritaFinlay and Marwick, 1937. In the study area, Glycymerita is represented by Glycymerita veatchii (Gabb, 1864), middle to late Turonian to late Campanian; Glycymerita banosensis (Anderson, 1958) new combination, late Campanian to latest Maastrichtian; Glycymerita aleuta n. sp., known only from Alaska and of early Maastrichtian age; and Glycymerita major (Stanton, 1896) new combination, Selandian to Thanetian. All the studied species lived in warm-temperate, shallow-marine waters and were shallow burrowers in fine-grained siliciclastic sediments. Variability in morphology is common in sizeable populations of the various species, especially Glycymerita veatchii, which increased nearly fivefold in size during its 19.5 million-year-long range and culminated in shells up to 84 mm in length.
Among weevils of the subfamily Baridinae (548 extant genera and ca. 9,000 species), unique prosternal horns and associated sheaths have evolved independently multiple times. These structures are utilized in a unique form of male-male aggression in which males push, rather than overturn as in most other horned beetles, their competitor. Herein we report the first fossils of male Baridinae exhibiting such prosternal horns. Two males recovered from the middle Eocene Green River Formation in northwestern Colorado serve to provide a minimum age (at ca. 47 million years old) for both the origin of horns and its associated form of male-male combat in Baridinae.
Despite increasingly intensive paleontological sampling, Cretaceous terrestrial vertebrates from continental Africa remain relatively poorly known, frustrating efforts to characterize paleoecosystems in the region, as well as the paleobiogeography of the southern continents during this interval. Here we describe the partial skeleton of a large-bodied theropod dinosaur from the Early Cretaceous (early Aptian, ∼125–120 Ma) of Libya. The specimen consists of associated elements (two incomplete dorsal vertebrae, a proximal caudal centrum, a partial proximal caudal neural arch, the distal right femur, and the mostly complete right tibia) and is referable to the widespread ceratosaurian clade Abelisauroidea. The discovery adds to the growing record of abelisauroids from mainland Africa, and firmly establishes the presence of the clade on the continent prior to its final separation from South America. Indeed, the age of the Libyan theropod predates or is penecontemporaneous with the accepted timing of fragmentation of most major Gondwanan landmasses, supporting the hypothesis that abelisauroids could have dispersed throughout the southern continents before land connections between these areas were severed. Moreover, the considerable size of the Libyan form challenges assertions that abelisauroids were ecologically subordinate to basal tetanuran theropods in Early and middle Cretaceous paleoenvironments of Gondwana.
Fossilized leaf mines and other traces of phytophagous insects provide a unique window into ecological and evolutionary associations of the past. Leaf-mining flies (Diptera: Agromyzidae) are an important component of the recent leaf-mining fauna, but their fossil record is sparse compared to other mining insect lineages; many putative agromyzid body fossils and traces are dubiously assigned. Agromyzid leaf mines often can be distinguished from those of other insects by the presence of an intermittent, fluidized frass trail that may alternate between the sides of the mine. Here, we describe two new Paleogene leaf mine fossils, Phytomyzites biliapchaensis Winkler, Labandeira and Wilf n. sp. from the early Paleocene of southeastern Montana, USA, occurring in leaves of Platanus raynoldsii (Platanaceae); and Phytomyzites schaarschmidti Wappler n. sp., from the middle Eocene of Messel, Germany, occurring in leaves of Toddalia ovata (Rutaceae). These fossils both exhibit frass trails indicative of an agromyzid origin, and P. biliapchaensis also exhibits associated stereotypical marks identical to damage caused by feeding punctures of extant adult female Agromyzidae prior to oviposition. Phytomyzites biliapchaensis represents the earliest confirmed record of Agromyzidae, and one of the earliest records for the large dipteran clade Schizophora. Plant hosts of both species belong to genera that are no longer hosts of leaf-mining Agromyzidae, suggesting a complex and dynamic history of early host-plant associations and, for the early Paleocene example, an evolutionary, possibly opportunistic colonization in the midst of the ecological chaos following the end-Cretaceous event in North America.
A fusuline fauna consisting of 9 species of 4 genera from the Xiala Formation of the Mujiucuo section, Xainza County, Tibet, China is described. The fusuline fauna is dominated by Nankinella and Chusenella and indicates a Midian (Late Guadalupian) age. The earliest record of fusuline fauna during the Midian in the Lhasa Block suggests that the block rifted later than the Qiangtang Block to the north and the Baoshan and Tengchong blocks to the east, all of which yield much earlier fusuline faunas of Yakhtashian (Artinskian) age, but had drifted away from Gondwana to a relatively warm temperate zone in the Late Guadalupian (Middle Permian).
A rudist fauna composed of the radiolitids Potosites tristantorresi new genus, new species and Radiolites acutocostata (Adkins), the hippuritids Barrettia cf. ruseae Chubb, Torreites sanchezi (Douvillé), and Vaccinites vermunti Mac Gillavry, plagioptychids, and antillocaprinids is described from a rudist limestone succession in the central Mexican State of San Luis Potosí. The previously known species, one radiolitid from Texas and three hippuritids from the Caribbean Biogeographic Province, indicate the early Campanian. The new genus is a large radiolitid with a coiled and canaliculated left valve. New observations on R. acutocostata and V. vermunti shell morphology and variability are provided. Observations made on well preserved specimens of the latter species clarify the outer shell layer structure of the hippuritids right valve and has taxonomic implications. This is the first report of genus Torreites in Mexico and one of the northernmost records of genus Barrettia, already reported in southern Mexico from Chiapas State. This rudist limestone succession (informally ‘Temazcal limestones’ herein) is an easy-to-recognize cartographical unit; up to now it and Santonian and Turonian units have been mapped as the El Abra Formation in most available geological maps. Recognition of the successive carbonate platform intervals, between El Abra and Cardenas formations, improves the geological mapping and the understanding of the Mexican Gulf western margin evolution during the Late Cretaceous.
New field collections allow the study and description of Valvata juliae new species from the Pliocene upper Burgi Member of the Koobi Fora Formation of Kenya. The shell morphology of this species varies from trochospiral to planispiral to open coiled. The species is restricted to a short stratigraphic interval. Valvata juliae is considered as an invader of the Turkana Basin during a lacustrine transgression event. The open coiling of the species is interpreted as an ecophenotypic response to a high level of environmental stress caused by lake level fluctuations and emergence of delta systems. These environmental conditions brought Valvata juliae to extinction soon after it invaded the Turkana Basin.
Fossil isopod crustaceans in the suborder Phreatoicidea have a known stratigraphic range from the Carboniferous to the Jurassic. Until now, all Mesozoic records of this group were thought to occur in fresh water habitats. A new phreatoicidean isopod fossil of the Triassic Luoping marine fauna, Yunnan Province, China, is described. The new species, based on several exceptionally complete specimens, is assigned to the genus Protamphisopus Nicholls and the family Amphisopidae Nicholls. This Chinese record is the first report of a Mesozoic-age phreatoicidean isopod outside of Gondwanan terranes, requiring a revision of known biogeographic patterns of the Phreatoicidea. Whether this record is from a marine habitat or is the result of a secondary deposition is not certain. Sottyella Racheboef, Schram and Vidal from the Carboniferous (Stephanian) Lagerstätte of Montceau-les-Mines that was assigned to this suborder may be a decapod. Therefore, it has no relationship to this new species.
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