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The Eocene cetacean genera Andrewsiphius and Kutchicetus are systematically revised, their anatomy described, and their phylogenetic position analyzed. Each genus contains a single species, A. sloani and K minimus, and both are known only from the middle Eocene of the Indian Subcontinent. Andrewsiphius and Kutchicetus differ in a number of respects, the most important dental difference being that P2, P3, p2, and p3 are double-rooted in Andrewsiphius and single-rooted in Kutchicetus. Lower molars are separated by diastemata in Kutchicetus, but not in Andrewsiphius. Postcranially, Andrewsiphius has caudal vertebrae that are far more robust than those of Kutchicetus.
We propose the new clade Andrewsiphiinae for these two genera, based on their unique characters: the extremely slender jaw, fused mandibular symphysis, narrow palate and rostrum, and lower molars that have a low crown with three cusps lined up rostro-caudally. A phylogenetic analysis indicates that andrewsiphiines are either a subfamily of Remingtonocetidae or an independent branch on the Eocene cetacean lineage. Interpreting conservatively, we classify them as remingtonocetids. Andrewsiphiines have a long, robust, dorso-ventrally flattened tail and short limbs, suggesting that they swam using dorsoventral undulation of the tail.
The dramatic late Early Ordovician radiation of cephalopods on tropical paleocontinents is illustrated by the diverse fauna (21 genera, 30 species) of the Fort Cassin Formation (Floian and lower Blackhillsian Stage) in northeast Laurentia. Cephalopods occur through the thin (ca. 30–65 m) depositional sequence of the Fort Cassin but are most common and diverse in mollusk-rich, trilobite-poor parts of the formation that characterize the thrombolite-bearing intervals in the shoaling part of the highstand systems tract. This lithofacies-biofacies linkage persists from the Tribes Hill and Rochdale Formations (lower and lower upper Tremadocian, and upper Skullrockian and Stairsian Stages, respectively), and suggests that the Early Ordovician radiations of cephalopods took place in shallow-marine, thrombolite reef facies of tropical carbonate platforms. These habitats differed strongly from the near-shore, peritidal habitats of the older Cambrian evolutionary radiation. Genus-level diversity and absolute abundance changed little through the Skullrockian-Blackhillsian, but morphologic diversity and body size increased dramatically by the late Early Ordovician. The morphological diversification suggests cephalopods diversified into a wider variety of macropredators and more complex late Early Ordovician ecosystems. Anrangeroceras whitehallense n. gen. and n. sp. is proposed. The following are emended: the Protocycloceratidae, Centrotarphyceras and C. seelyi, Protocycloceras and P. lamarcki, and Rudolfoceras cornuoryx. The following are indeterminate and abandoned: Baltoceras? pusillum Ruedemann, 1906; Comeroceras annuliferum Flower, 1941; Cyptendoceras whitfieldi Ulrich et al., 1944; Endoceras? champlainense Ruedemann, 1906; Wolungoceras valcourense Flower, 1964. Beekmanoceras Ulrich and Foerste, 1936 is a gastropod.
Platycrinites is traditionally one of the more recognizable crinoids, a camerate crinoid with very few if any fixed brachials or interradials and a helically twisted column. Accordingly, many taxa have been assigned to this genus. With a better understanding of the Platycrinitidae, these characters actually unite the family Platycrinitidae rather than the genus. Further, use of different genus-diagnostic characters in Western Europe versus North America has resulted in a confused systematics for this important late Paleozoic family. Here, we objectively define genera within the Platycrinitidae and assign all species to either newly defined or newly named genera. A phylogenetic hypothesis, incorporating both parsimony-based character analysis and stratigraphic ranges, of the genera within the Platycrinitidae is presented.
With consideration of the type species, Platycrinites laevis Miller, 1821, Platycrinites sensu stricto is distinguished from Platycrinites sensu lato, which is used for species that cannot be assigned with confidence to any objectively defined genus. New genera are Artaocrinus n. gen., Collicrinus n. gen., Elegantocrinus n. gen., and Laticrinus n. gen.; and Exsulacrinus Bowsher and Strimple, 1986 is designated a junior synonym of Platycrinites s.s. Collicrinus shumardi n. gen. and sp., Laticrinus oweni n. gen. and sp., and Laticrinus wachsmuthi n. gen. and sp. are described; and Platycrinites formosus approximatus (Miller and Gurley, 1896a) is designated a junior synonym of Platycrinites formosus (Miller and Gurley, 1895a), which is reassigned here to Collicrinus n. gen. Platycrinites s.s. now includes 14 species and species-level taxa, and 76 species are assigned to Platycrinites s.l. Ten species are designated nomina dubia, as are taxa based solely on columnals or pluricolumnals. Two species are designated nomina nuda, and two are transferred to genera outside of the Platycrinitidae. In addition, twenty-seven species and four open-nomenclature taxa are each reassigned to a different genus.
Newly obtained foraminifer faunas from the Permian-Triassic (P-Tr) transition at the Dajiang and Bianyang sections in the Nanpanjiang Basin, South China, comprise 61 species in 40 genera. They belong to the Palaeofusulina sinensis Zone, the youngest Permian foraminifer zone in South China. Quantitative analysis reveals that the last occurrences of more than a half of species (28/54) fall into a 60-cm-interval at the uppermost Changhsingian skeletal packstone unit and thus calibrate the end-Permian extinction to the skeletal packstonecalcimicrobial framestone boundary. About 93% (54/58) of species of the latest Permian assemblage became extinct in the P-Tr crisis. Four major foraminiferal groups, the Miliolida, Fusulinida, Lagenida, and Textulariina, have extinction rates up to 100%, 96%, 92%, and 50%, respectively, and thus experienced selective extinctions. Both Hemigordius longus and ?Globivalvulina bulloides temporarily survived the end-Permian extinction event and extended into the earliest Triassic but became extinct soon after. The post-extinction foraminifer assemblage is characterized by the presence of both disaster taxa and Lazarus taxa. Foraminifer distribution near the P-Tr boundary also reveals that the irregular contact surface at the uppermost Permian may be created by a massive submarine dissolution event, which may be coeval with the end-Permian mass extinction. A new species, Rectostipulina hexamerata, is described here.
A series of small road cuts of lower Boyle Formation (Middle Devonian: Givetian) near Waco, Kentucky, has produced numerous specimens of three blastozoan clades, including both “anachronistic” diploporan and rhombiferan “cystoids” and relatively advanced Granatocrinid blastoids. This unusual assemblage occurs within a basal grainstone unit of the Boyle Limestone, apparently recording a local shoal deposit. Diploporans, the most abundant articulated echinoderms, are represented by a new protocrinitid species, Tristomiocystis globosus n. gen. and sp. Glyptocystitoid rhombiferans are represented by isolated thecal plates assignable to Callocystitidae. Three species of blastoids, all previously undescribed, include numerous thecae of the schizoblastid Hydroblastus hendyi n. gen. and sp., the rare nucleocrinid Nucleocrinus bosei n. sp., and an enigmatic troosticrinid radial. The blastoid Nucleocrinus is typical for the age; however, the callocystitid, schizoblastid, and protocrinitid are not. Hydroblastus is the oldest known schizoblastid. Middle and Upper Devonian callocystitids have been previously reported only from Iowa and Michigan USA with unpublished reports from Missouri USA and the Northwest Territories, Canada. This occurrence is thus the first report of a Middle Devonian rhombiferan from the Appalachian foreland basin. Tristomiocystis is the first known protocrinitid in North America and the only protocrinitid younger than Late Ordovician. This occurrence thus represents a range extension of nearly 50 million years for protocrinids. This extraordinary sample of echinoderms in a Middle Devonian limestone from a well-studied area of North America highlights the incompleteness of the known fossil record, at least in fragile organisms such as echinoderms.
Leptomaria antipodensis and Leptomaria hickmanae are described from the Upper Cretaceous [Maastrichtian] Lopez de Bertodano Formation, Seymour Island, and represent the first Mesozoic records of the family Pleurotomariidae from Antarctica. Leptomaria stillwelli, L. seymourensis, Conotomaria sobralensis and C. bayeri, from the Paleocene [Danian], Sobral Formation, Seymour Island, are described as new. Leptomaria larseniana (Wilckens, 1911) new combination, also from the Sobral Formation, is redescribed based on better-preserved material. The limited diversity of the pleurotomariid fauna of Seymour Island is more similar to that of the Late Cretaceous faunas of Australia and New Zealand in terms of the number of genera and species, than to the older, more diverse faunas of South America, southern India, or northwestern Madagascar, supporting the status of the Weddelian Province as a distinct biogeographic unit. The increase in the species richness of this fauna during the Danian may be due to the final fragmentation of Gondwana during this period.
This paper presents an overview of the bryozoan fauna from the upper Koněprusy Limestone (kindlei Conodont Zone, middle Pragian, Lower Devonian) exposed in two quarries at Zlatý Kuň near Koněprusy in Central Bohemia, and discusses its paleoecology and paleobiogeography. The studied fauna is dominated by encrusting fistuliporine and trepostome bryozoans (eight species), accompanied mainly by reticulate fenestrates (four species), branching ramose trepostomes and cryptostomes (three species), and one massive trepostome species. The richest bryozoan association comes from reef core/margin facies (13 species), followed by crinoid-bryozoan facies of the ramp (eight species). The reef-terrace facies and the crinoid-bryozoan-algal facies contain three and two species respectively. Seven species are described taxonomically, three fistuliporines and four trepostomes. The following taxa are new: Koneprusiella armata n. gen. n. sp., Fistulipora rarivesiculata n. sp., Fistulipora hladili n. sp. and Leptotrypa varia n. sp. Paleobiogeographic patterns of the bryozoan fauna from the Koněprusy Limestone are similar to those of stromatoporoids, comprising widely distributed genera but mainly endemic species. This supports a relative geographic isolation of the Koněprusy reef. The bryozoan fauna from the Koněprusy Limestone shows paleogeographic affinities with that from the Lower Devonian (Pragian) of Morocco and the Middle Devonian of Michigan (USA).
Stromatomorpha californica Smith is a massive, calcified, tropical to subtropical organism of the Late Triassic that produced small biostromes and contributed in building some reefs. It comes from the displaced terranes of Cordilleran North America (Eastern Klamath terrane, Alexander terrane, and Wrangellia). This shallow-water organism formed small laminar masses and sometimes patch reefs. It was first referred to the order Spongiomorphidae but was considered to be a coral. Other affinities that have been proposed include hydrozoan, stomatoporoid, sclerosponge, and chambered sponge. Part of the problem was diagenesis that resulted in dissolution of the siliceous spicules and/or replaced them with calcite. Well-preserved dendroclone spicules found during study of newly discovered specimens necessitate an assignment of Stromatomorpha californica to the demosponge order Orchocladina Rauff. Restudy of examples from the Northern Calcareous Alps extends the distribution of this species to the Tethys, where it was an important secondary framework builder in Upper Triassic (Norian-Rhaetian) reef complexes. Revisions of Stromatomorpha californica produce much wider pantropical distribution, mirroring paleogeographic patterns revealed for other tropical Triassic taxa. Review of Liassic material from the Jurassic of Morocco, previously assigned to Stromatomorpha californica Smith var. columnaris Le Maitre, cannot be sustained. Species previously included in Stromatomorpha are: S. stylifera Frech (type species, Rhaetian), S. actinostromoides Boiko (Norian), S. californica Smith (Norian), S. concescui Balters (Ladinian-Carnian), S. pamirica Boiko (Norian), S. rhaetica Kühn (Rhaetian), S. stromatoporoides Frech, and S. tenuiramosa Boiko (Norian). Stromatomorpha rhaetica Kühn described from the Rhaetian of Vorarlberg, Austria shows no major difference from S. californica. An example described as S. oncescui Balters from the Ladinian-Carnian of the Rarau Mountains, Romania, is very similar to S. californica in exhibiting similar spicule types. However, because of the greater distance between individual pillars, horizontal layers, and the older age, S. oncescui is retained as a separate species. The net-like and regular skeleton of Spongiomorpha sanpozanensis Yabe and Sugiyama, from the Upper Triassic of Sambosan (Tosa, Japan), suggests a closer alliance with Stromatomorpha, and this taxon possibly could be the same as S. californica.
A new agelacrinitid edrioasteroid, Multiplexidiscus mckenziensis n. gen., n. sp. is described from the middle Silurian upper McKenzie Shale Member of the Mifflintown Formation of Pennsylvania. These edrioasteroids were attached to a large hardground clast that was reworked and flipped during a storm event. The occurrence of edrioasteroids in a near shore, perhaps in sub-normal salinity, is unusual for echinoderms. The edrioasteroids show a dispersed spatial distribution and weak thecal orientation. Multiplexidiscus differs from other agelacrinid edrioasteroids in the presence of a complex pattern of ambulacral cover plates combined with nearly straight paedomorphic ambulacra.
Three productidine brachiopods of Haydenella, Paraplicatifera, and Compressoproductus are recovered from the Tak Fa Formation (Wordian, Middle Permian) of the upper Saraburi Limestone Group exposed at Khao Wong of central Thailand (the western margin of the Indochina Terrane). The latter two genera are new to the Permian of Thailand, and the new species Paraplicatifera thaica is proposed herewith. Some taxonomic and nomenclatural problems in relation to the three genera are discussed. The assemblage suggests endemism for a Middle Permian marine faunule of the Indochina Terrane.
Siliceous sponges are rare in the Cretaceous-Paleogene record, with only a handful of published accounts from the Southern Hemisphere. Variously preserved siliceous sponges, both Hexactinellida and Demospongiae, have been recovered from the Takatika Grit (Campanian-Danian), Chatham Islands, New Zealand. Hexactinellid sponges are represented by the Euretidae Eotretochone australis n. gen. and sp., Pararete sp., and Euretid gen. and sp. indet., Auloplax? sp. (Dactylocalycidae) and Tretodictyiid gen. and sp. indet., as well as by loose hexactines and fragments of dictyonal skeletons. Demosponges are represented only by loose spicules typical of Astrophorida, and perhaps lithistids. These fossils represent the first account of sponges of this age from the New Zealand region of the southwest Pacific.
The Non-Mineralized arthropod described herein is derived from the Sirius Passet fossil conservation deposit of North Greenland (82°47.6,N, 42°13.7ʹW), the oldest locality with exceptional preservation of soft tissues known from the Cambrian of Laurentia (Cambrian Series 2, Stage 3; Nevadella Zone). As such, it is broadly contemporaneous with the Chengjiang fauna of China (Hou et al., 2004) and some 10 million years older than the Burgess Shale fauna of British Columbia. The Sirius Passet fauna was first documented by Conway Morris et al. (1987) and its geological setting is discussed by Babcock and Peel (2007). In addition to the nevadiid trilobite Buenellus higginsi Blaker, 1988, the fauna is dominated by non-mineralized arthropods (Budd, 1993, 1995, 1997, 1999; Williams et al., 1996; Taylor, 2002). Other finds include sponges (Rigby, 1986), a lobopod (Budd and Peel, 1998), the earliest annelids (Conway Morris and Peel, 2008) and articulated halkieriids (Conway Morris and Peel, 1990, 1995), but most of the assemblage awaits description.
A new aphid species, Dracaphis angustata, has been found in China from the Middle Triassic. It is especially informative because its whole body is preserved except for the distal part of the antennae and part of the legs. Only wings of three other aphid species of Triassic age have previously been found: Triassoaphis cubitus, described by Evans (1956) from Australia and placed in its own family, Triassoaphididae Heie, 1999; Creaphis theodora, described by Shcherbakov and Wegierek (1991) from Central Asia and placed in its own family, Creaphididae; and Coccavus supercubitus, described by Shcherbakov (2007) from Kyrgyzstan and placed in Naibiidae together with Naibia from the Lower Tertiary. The new species described below must be placed in its own family Dracaphididae because it possesses a combination of characters unknown in any other aphid clade.