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Arthrodendron maguricum n. sp. is described from deep-sea flysch of the lower Eocene Życzanów Conglomerate Member of the Szczawnica Formation (Magura Unit) in the Polish Carpathians. Arthrodendron maguricum is a larger agglutinated foraminifer showing regular, tubular chambers that may branch dichotomously. Its wall is tripartite and composed of an outer organic-rich layer, a main agglutinated layer, and an internal organic-rich layer. The organism evidently lived as epibenthos on the muddy sea floor. Because of their branching morphology and comparatively large dimensions, larger agglutinated foraminifera of the genus Arthrodendron have previously been confused with algae and trace fossils. Care should be taken in such cases to resolve the agglutinated wall and chambers of this deep-water agglutinated foraminifer. Arthrodendron maguricum displays superficial similarities to some modern komokiaceans, especially to Septuma. Further investigations are needed for clarification of their affinities and possible taxonomic consequences.
The Cretaceous record of the shallow-marine margaritine gastropod genus Atira Stewart, 1927 in the region extending from Vancouver Island, to northern Baja California is studied in detail for the first time. It is represented by A. popenoei n. sp. (late Turonian to earliest Campanian), A. ornatissima (Gabb, 1864) (latest Santonian to late Campanian or possibly early Maastrichtian), and A. inornata (Gabb, 1864) (“mid” Maastrichtian), which is the youngest known species of Atira.
Atira originated in the tropical waters of the Tethys Sea in western Europe as early as the Early Cretaceous, possibly during the Hauterivian but was present there by the late Aptian to early Albian. The genus subsequently immigrated to other regions and became adapted to warm-temperate waters. By the late Turonian it had migrated westward to northern California. During the Campanian it reached south Sakhalin and in the earliest Maastrichtian it was present in southwest Japan. Although Atira? nebrascensis (Meek and Hayden, 1856) has been questionably reported from Campanian to “mid” Maastrichtian deposits in the Wyoming area of the Western Interior Basin, this species does not belong in genus Atira.
New specimens of an as yet unidentified carnivoran from the earliest Paleocene of Saskatchewan are described. The new specimens augment the evidence on which the contentious earliest (middle Puercan) occurrence of Carnivora is based, provide novel information of the lower dentition of the earliest carnivorans, and provides evidence for the earliest taxonomic diversity in Carnivora.
Cambrothyra ampulliformis Qian and Zhang, 1983, is a jar- or vase-shaped fossil known from the Lower Cambrian of Shaanxi and Hubei provinces, China. It has been interpreted as a protistan test or cyst or a metazoan sclerite. A large collection of specimens from the Xihaoping Member of the Dengying Formation in southern Shaanxi Province permits its detailed redescription. These fossils are highly variable in shape but this variation is continuous and does not support the current recognition of multiple species for this material. They were originally hollow with a restricted basal foramen and a calcareous wall probably composed of fibrous aragonite. All of these features support the identification of Cambrothyra as sclerites of a coeloscleritophoran, a problematic group of Cambrian scleritome-bearing metazoans. Furthermore, the walls of Cambrothyra sclerites contain numerous pores, a feature shared with other coeloscleritophorans. Cambrothyra resembles chancelloriids in particular due to the shared presence of a verruculose texture around the foramen and the absence of mirror-image pairs of asymmetric sclerites. However, unlike chancelloriids, which have rosette-like compound sclerites, the scleritome of Cambrothyra was dominated by isolated sclerites, with only a few pairs and clusters of sclerites and twin sclerites. Consequently, we hypothesize that Cambrothyra forms a clade with other chancelloriids, but represents a basal lineage that plesiomorphically retained isolated sclerites. The morphology of Cambrothyra sclerites, which shares features with both chancelloriids and halkieriids, thus supports the hypothesis that all coeloscleritophorans form a natural group.
This study presents the first record of Eocene birds from the western margin of southernmost South America. Three localities in Magallanes, southern Chile, have yielded a total of eleven bird remains, including Sphenisciformes (penguins) and one record tentatively assigned to cf. Ardeidae (egrets). Two different groups of penguins have been recognized from these localities. The first group is similar in size to the smallest taxa previously described from Seymour Island, Marambiornis Myrcha et al., 2002, Mesetaornis Myrcha et al., 2002, and Delphinornis Wiman, 1905. The second recognized group is similar in size to the biggest taxa from Seymour Island; based on the available remains, we recognize the genus Palaeeudyptes Huxley, 1859, one of the most widespread penguin genera in the Southern Hemisphere during the Eocene. The stratigraphic context of the localities indicates a certain level of correlation with the geological units described on Seymour Island. The newly studied materials cast more light on the paleobiogeography of the group, extending the known ranges to the South American continent. In addition to the newly discovered birds, the presence of several taxa of elasmobranchs previously recovered exclusively from Eocene beds in the Southern Hemisphere help to clarify the age of the studied localities, widely discussed during the last decades. This paper verifies the presence of extensive Eocene sedimentary successions with fossil vertebrates along the western margin of southern South America, contrary to the previous assumption that such a record is lacking in Chile.
Remains of a pteranodontid pterosaur are recorded in the basal Austin Group of North Texas. The specimen described here comprises a partial left wing and strongly resembles Pteranodon although diagnostic features of that genus are lacking. With an estimated early Coniacian age, this specimen represents the earliest occurrence of the Pteranodontidae in North America and the second earliest occurrence worldwide, predated only by Ornithostoma from the Cambridge Greensand of England. Pterosaur material recovered from the Eagle Ford and Austin groups of Texas records an early Late Cretaceous change in the composition of North American pterosaur communities between the late Cenomanian and the early Coniacian. This faunal transition appears to be primarily a decrease in morphological disparity rather than a significant reduction in taxonomic diversity. However, the lack of Early Cretaceous Lagerstätten in North America may produce underestimates of true pterosaur richness during this interval, thereby obscuring a subsequent drop in diversity.
Five new species of Maurotarion Alberti, 1969 from the Silurian Lipeón Formation and Lower Devonian Talacasto Formation of Argentina are recognized. The comparisons with Bolivian and South African species support a Malvinokaffric clade based on librigenal synapomorphies, here erected as Maurotarion (Malvinotarion) new subgenus. The Malvinokaffric origin of the family would not be a migration from lower paleolatitudes but an Early Silurian stock of rare cosmopolitan ancestors which underwent a great Devonian radiation. Two lineages can be recognized within Malvinokaffric Maurotarion. The Silurian-Pragian dereimsi lineage is a plesiomorphic one resembling Silurian representatives and involves M. (Malvinotarion) dereimsi, M. (Malvinotarion) talacastoense new species, M. (Malvinotarion?) new species A, M. (Malvinotarion?) new species B, M. (Malvinotarion) sp., and eventually M. (Malvinotarion?) cf. dereimsi. The isaacsoni lineage ranges from the Lower Pragian to Eifelian exhibiting a defined morphologic trend in the librigena. This lineage comprises M. (Malvinotarion) isaacsoni, M. (Malvinotarion) sp. A from South Africa, M. (Malvinotarion) gaucho new species, M. (Malvinotarion) haudei new species and M. (Malvinotarion) legrandi. A Lochkovian diversification probably took place yet an adequate assessment remains difficult. In contrast, a great evolutionary burst is recognized during the Emsian and is related to Pragian-Emsian global relative sea level curves which are coincident with those proposed from Bolivian and Argentinian basins.
New material, including a complete exoskeleton, from the Bromide Formation of Oklahoma, allows a complete evaluation of Probolichas Phleger, 1936 and necessitates a quantitative revision of the lichid tribe Tetralichini Phleger, 1936. A strict consensus tree of nine equally parsimonious trees generated from a branch and bound analysis indicates that the genus Probolichas is monophyletic, and should no longer be restricted as synonymous with, or as a sub-clade of Amphilichas Raymond, 1905. The genus Apatolichas Whittington, 1963 is revised as a synonym of Amphilichas, and the Tetralichini is defined as clade with three genera: Amphilichas, Probolichas, and Lyralichas Weber, 1948. Probolichas kristiae from the Bromide Formation and Amphilichas effnensis from the Effna Formation of Virginia are new species.
Commensal epizoozoans and episkeletozoans are rarely preserved attached to the external exoskeleton of the Late Ordovician trilobite Flexicalymene. Of nearly 15,000 Flexicalymene specimens examined, 0.1% show epizoozoans or episkeletozoans. Factors limiting Flexicalymene fouling include a shallow burrowing life style, frequent molting of the host, larval preference for other substrates, observational bias caused by overlooking small fouling organisms, and the loss of the non-calcified, outermost cuticle prior to fossilization or as the trilobite weathers from the encasing sediment. Trepostome bryozoans, articulate and inarticulate brachiopods, cornulitids, and a tube-dwelling/boring nonbiomineralized organism represent the preserved members of the Late Ordovician marine hard substrate community fouling Flexicalymene. This assemblage of organisms is less diverse than the hard substrate community fouling Late Ordovician sessile epibenthic organisms. Fouling is not restricted to only large Flexicalymene specimens as observed in previous studies but occurs in medium to large individuals interpreted as early to late holaspid specimens.
Epizoozoans fouling the carcasses or molt ensembles of 16 Flexicalymene specimens provide insight into the life habits of the host and these fouling organisms. Trepostome bryozoans, articulate and inarticulate brachiopods, and cornulitids preferentially attached to elevated portions of the dorsal exoskeleton, and preferentially aligned in either the direct line or lee side of currents generated by Flexicalymene walking on the sea floor or swimming through the water column.
A new colosteid, Deltaherpeton hiemstrae gen. et sp. nov., is described from the Mississippian Upper Viséan site at Delta, Iowa. Deltaherpeton is represented by a skull roof and both jaws. The new taxon is unique among colosteids in having an internasal and single midline postparietal. An additional midline pair of cf. ‘interfrontonasals’ may be present. Characters previously used to define the colosteids are reviewed and a refined diagnosis for the family Colosteidae is presented. Synapomorphies which unite Deltaherpeton, Colosteus, Greererpeton, and Pholidogaster as Colosteidae are: premaxilla with fang pair; dentary with notch for receipt of premaxillary fang; mandible with single elongate exomeckelian fenestra; pre-narial infraorbital lateral line terminating at ventral margin of premaxilla just anterior to external naris; and post-narial infraorbital lateral line terminating at the ventral margin of the maxilla just posterior to the external naris. Our review of dermal bones in the colosteid snout concludes that no specimen is sufficiently free of distortions or breakage to indicate clearly whether or not the prefrontal borders the external naris, or that an anterior tectal is present. The morphology of Deltaherpeton and the revised data presented for colosteids do not clarify the relationship of colosteids to other early tetrapods.
An exceptionally well-preserved silicified bivalve from the Upper Permian of Texas is described and assigned to a new genus and species, Cassiavellia galtarae, placed in the family Bakevelliidae. The species represents one of the earliest and best characterized unequivocal occurrences of the multivincular ligament in the superfamily Pterioidea. The silicified material provides a wealth of information on the morphology of inadequately known Paleozoic pterioideans, including hitherto undescribed aspects of the larval shell, auricular sulcus, muscle scars, and dental ontogeny. The discovery of the condyle-fossa complex on the anteroventral shell margin, a feature previously undescibed in Bivalvia, raises the question of the homology and taxonomic significance of the problematic subumbonal ridge-like structures in Pterioidea. In life, C. galtarae was probably an epifaunal right-pleurothetic bivalve, byssally attached to hard or raised flexible substrata. In addition to C. galtarae, another new species, C. nadkevnae, is placed in Cassiavellia.
Recent field work at the Deseadan (late Oligocene) locality of Quebrada Fiera (Mendoza Province, Argentina) has provided new fossil remains that greatly increased the faunal assemblage of this site. A good number of specimens correspond to the Family Archaeohyracidae (Notoungulata) and are presented in this paper. Most of them are recognized as a unique taxon, corresponding to the genus Archaeohyrax, characterized by the presence of a strong, shallow, wide sulcus on the labial side of the talonid of m3. At specific level, it is identified with the species A. suniensis previously recognized at Salla (Bolivia). Specimens with different tooth wear degree show an intraspecific variation in occlusal morphology comparable to that observed among the Bolivian material. In addition to A. suniensis, an isolated p2 is tentatively related to Archaeotypotherium, due to their hypsodont but rooted condition and larger size. Two other isolated lower molars from this site had been previously related to this genus but they are comparable to the new specimens ascribed to Archaeohyrax. The identification of Archaeotypotherium is not well supported at present, but if later confirmed, it would increase the temporal distribution of the genus, so far recorded in Tinguirirican (early Oligocene) localities of Chile and Argentina. The recognition of A. suniensis in Quebrada Fiera establishes a greater affinity with the lower latitude Deseadan fauna of Salla than with that from Patagonia, where the genus is represented by A. patagonicus. Other faunal elements from Quebrada Fiera, however, do not support this affinity with Bolivia. Xenarthrans or some marsupials are equivalent to those from Patagonia, while other taxa such as the recently described notohippid or a rare, tiny metatheria are at present exclusive for Mendoza. The increasing knowledge of the Quebrada Fiera assemblage contributes to a better understanding of the paleogeographic scenario of Southern South America during late Oligocene.
A bed on Jbel Issoumour, near Alnif in southeastern Morocco, contains numerous complete trilobites. The bed is located stratigraphically at the base of the El Otfal Formation, immediately above a cliff-forming resistant unit known to local trilobite miners as the ‘grand calcaire’, and is latest Emsian or early Eifelian in age. The fauna exhibits an alpha trilobite diversity of at least eight species, including Erbenochile issoumourensis n. sp., Acanthopyge (Lobopyge) bassei n. sp., and Walliserops lindoei n. sp. The absence of lateral palpebral extensions in E. issoumourensis but their presence in the type species of Erbenochile, E. erbeni, when considered with other differences in the exceptionally large eyes of both species, supports the hypothesis that these palpebral structures functioned as eyeshades in E. erbeni but not in E. issoumourensis. Walliserops lindoei has a short, stout haft at the base of the trident anterior cephalic projection, which is the most characteristic feature of Walliserops. This projection in Walliserops primarily functioned as a deterrent to predators.
An isolated ramus of the pterygotid eurypterid Jaekelopterus cf. howelli from the Early Devonian (Pragian) Beartooth Butte Formation (Cottonwood Canyon, north-western Wyoming) is described. Pterygotid taxonomy and synonymy is briefly discussed with the genera Pterygotus, Acutiramus and Jaekelopterus shown to be potential synonyms. The use of cheliceral denticulation patterns as a generic-level character is discouraged in light of variations within genera and its unsuitability as a major characteristic in the other eurypterid families.
Alphacrinus mansfieldi new genus and species from the Middle Tremadoc Series (Early Ibexian), near the base of the Ordovician, is the oldest known disparid crinoid. A new family, Alphacrinidae, receives this monospecific genus. Alphacrinus's character mosaic includes primitive traits unknown among other disparids, auguring for disparid origin from a more complexly plated, less standardized antecedent, and echoing the evolutionary progression documented for camerates and cladids. Disparids are diagnosed as those crinoids expressing an arm-like branch from the C ray. Morphologic progression indicates this distinctive trait evolved by modification of CD interray plates, not as an outgrowth from the C ray.
The Paleogene Order Taeniodonta Cope, 1876—peculiar heavy-bodied mammals, some with evergrowing cheek teeth—are grouped with the Late Cretaceous eutherian Cimolestes Marsh, 1889, along with a host of other taxa in a superordinal group, the Cimolesta. Taeniodonts were thought to have arisen from Cimolestes indirectly, through Paleocene Procerberus Sloan and Van Valen, 1965. The recently described Paleocene Alveugena Eberle, 1999, until now known only from the upper dentition, has been put forth as a transitional form between cimolestids and taeniodonts on phylogenetic and biostratigraphic grounds. An older taeniodont, the Late Cretaceous Schowalteria Fox and Naylor, 2003, has since been described, complicating taeniodont origins. We describe here a lower jaw that we refer to Alveugena from the lower part of the Ludlow Member of the Fort Union Formation in North Dakota. The lower jaw comes from strata of early Early Paleocene age (Puercan 1 North American Land Mammal Age) ~8.5 m above a Cretaceous-Paleogene boundary, identified using palynological criteria. A cladistic analysis is here presented using new data on Schowalteria and Alveugena, added to that of Cimolestes, Procerberus formicarum Sloan and Van Valen, 1965, P. grandis Middleton and Dewar, 2004, and Onychodectes. This analysis revealed Alveugena as the sister taxon of the taeniodonts but with a closer relationship to Cimolestes than Procerberus, suggesting that taeniodonts evolved from a Cimolestes-like ancestor. We discuss the age relations of early taeniodonts and related taxa and propose a scenario of ancestor-descendent relations that minimizes, but does not eliminate, implied stratigraphic gaps.
In the July issue of Journal of Paleontology, 84(4), Sánchez (2010) proposed the new genus name Emiliodonta for the Ordovician bivalve genus Emiliania Sánchez, 1999 because of assumed homonymy with Emiliania Hay and Mohler, 1967 (in Hay et al., 1967). The supposed senior name, the genus Emiliania Hay and Mohler, belongs to the coccolithophores, a group of unicellular eukaryotic algae, which have traditionally been treated as plants (e.g., Glaessner, 1945; Tappan, 1980; see also Green and Jordan, 1994; Andersen, 2004 for modern classification) and to which the International Code of Botanical Nomenclature (ICBN) applies. In the original description of Emiliania Hay and Molher the ICBN was used (Hay et al., 1967, p. 447) and the name was validly published under its rules. Animals such as the bivalve Emiliania Sánchez, 1999, in contrast, are treated under the International Code for Zoological Nomenclature (ICZN). Both codes are independent (ICBN, Principle I: Greuter et al., 1993, 2000; McNeill et al., 2006; ICZN Article 1: Ride et al., 1985, 1999), and therefore the same names (“homonyms” sensu lato) can coexist under different codes. Consequently, Emiliania Sánchez and Emiliania Hay and Molher are not homonyms in a taxonomic sense but are both legitimate names under the respective code. Furthermore, the name Emiliodonta Sánchez 2010 is superfluous and illegitimate, as “[…] the name of an animal taxon is not to be rejected merely because it is identical with the name of a taxon that is not animal.” (ICZN Article 1.4: Ride et al., 1999).