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Thirty species of Cancellariidae in 11 genera from the Miocene Gatun Formation in the Panama Canal area, Caribbean Panama, are discussed including two species not represented by specimens suitable for formal description. The following 11 species are described as new: Cancellaria harzhauseri n. sp., Cancellaria mixta n. sp., Bivetiella dilatata n. sp., Euclia alacertata n. sp., Pyruclia tweedledum n. sp., Pyruclia tweedledee n. sp., Massyla toulai n. sp., Aphera aphrodite n. sp., Axelella cativa n. sp., Agatrix agathe n. sp., Ventrilia coatesi n. sp. This assemblage of cancellariids is very diverse and highly endemic, with 18 (60 percent) species found only in the Miocene Gatun Formation. These assemblages all lie within the Gatunian Neogene Paciphile Molluscan Unit 1 (GNPMU1).
The Hanneh Member (Cambrian Stage 5) of the Burj Formation and the Umm Ishrin Formation of Jordan represent a transgressive-regressive succession that contains twenty-eight ichnotaxa, including vertical burrows (Arenicolites isp., Diplocraterion isp., Gyrolithes polonicus, Rosselia isp., Skolithos linearis, escape trace fossils), horizontal simple burrows and trails (Archaeonassa fossulata, Gordia marina, Helminthoidichnites tenuis, Palaeophycus tubularis, Planolites beverleyensis, P. montanus), plug-shaped burrows (Bergaueria sucta), horizontal branched burrows (Asterosoma isp., Phycodes isp., Treptichnus cf. T. pedum), bilobate structures (various ichnospecies of Cruziana and Rusophycus), and trackways and scratch marks (Diplichnites isp., Dimorphichnus cf. D. obliquus, Monomorphichnus isp.). Eleven trace-fossil assemblages are identified. The Arenicolites isp. and Diplocraterion isp. assemblages occur in transgressive tidal dunes and bars whereas the Rosselia isp. assemblage characterizes areas between tidal dunes. The Cruziana salomonis assemblage reflects a wide variety of environmental settings including channels within tidal-bar complexes, bottomsets of tidal dunes, and interdune areas. The Gordia marina assemblage is present between dune patches. The Gyrolithes polonicus assemblage penetrates into firmground mudstone below the maximum flooding surface. The Bergaueria sucta, Archaeonassa fossulata, Rusophycus aegypticus and Cruziana problematica assemblages occur in different subenvironments of the progradational delta. Cruziana salomonis and Rusophycus burjensis, originally considered indicative of an early Cambrian age, are actually middle Cambrian in their type locality. Occurrences of Cruziana jordanica and Rusophycus aegypticus provide evidence that these ichnospecies are of the same age in Jordan and may co-exist in terms of stratigraphic distribution with C. salomonis and R. burjensis.
Universal elemental homology (UEH) is used to establish homology of thecal plates and elements of the ambulacral system among clades of stemmed echinoderms by placing these structures into a testable hypothesis of homology. Here UEH is used to explore hypotheses of homology in blastoids, coronoids, Lysocystites, hemicosmitoids, and glyptocystitoids. This new approach to analyze homology is particularly powerful in understanding the nature of the thecal plates of blastoids and how they relate to other taxa in a common nomenclatural lexicon. In blastoids, deltoids are interpreted as oral plates that are homologues to oral plates of glyptocystitoids and hemicosmitoids whereas side plates are interpreted to be ambulacral floor plates. Thecal plates are homologous among blastoids, coronoids and Lysocystites but these morphologies cannot be reconciled with plate circlets of glyptocystitoids and hemicosmitoids. A phylogenetic analysis of these taxa presents the origin of blastoids as sister taxon of coronoids within a testable series of homologies.
Uintasoricines are diminutive plesiadapiforms that are found in the latest Paleocene through middle Eocene, predominantly in North America. They are not a diverse group but individual species may be locally abundant and they are a persistent element of the plesiadapiform radiation in North America surviving over a span of approximately 16 million years. Recent field work in southern Wyoming at South Pass has led to the discovery of a new genus and species of uintasoricine. The new form is smaller in tooth dimensions compared to other known uintasoricines, being slightly smaller than Uintasorex montezumicus from California. Both the newly described taxon and U. montezumicus are among the smallest plesiadapiforms yet known with body weights estimated to be 20 to 25 g. The sediments of the Cathedral Bluffs Tongue of the Wasatch Formation at South Pass contain a unique upland fauna—the presence of a distinctive uintasoricine in this assemblage adds further evidence to support the notion that this upland environment was a biodiversity hotspot during the latest early Eocene.
The oldest known Carboniferous rugose coral fauna in the Canadian Arctic Islands was collected in the Yelverton Inlet area of northern Ellesmere Island, from Bashkirian carbonates of the lower Nansen and Otto Fiord formations. It includes the genera Dibunophyllum Thomson and Nicholson, Lonsdaleia McCoy, Palaeosmilia Milne-Edwards and Haime and Tizraia? Said and Rodríguez. Such a generic assemblage is unknown elsewhere above the Serpukhovian. An upper? Bashkirian specimen of Paraheritschioides Sando, collected above the main fauna, is the oldest known representative of that genus. Faunal comparisons suggest Novaya Zemlya or northern Timan as the most likely source areas for the Yelverton Inlet fauna.
Arthrophycus alleghaniensis is a well-known trace fossil common in the lower Silurian of the Appalachian Basin, eastern U.S.A. Despite the distinctive morphology of this trace, with few exceptions, hypotheses about the nature of the tracemaker have not extended beyond that of a long-bodied, segmented organism. A single organic compression of a long-bodied arthropod discovered in shale interbedded with sandstones containing A. alleghaniensis in the Silurian (Llandovery) Tuscarora Formation at Mann Narrows, Pennsylvania is described. The specimen preserves evidence of two trunk tagmata: an anterior tagma with tergites extending into broad, rectangular pleurae, and a posterior tagma bearing long, curved spines. Head and appendages are not preserved. The new arthropod, Pleuralata spinosa n. gen. n. sp., matches the size and general morphology required for an A. alleghaniensis tracemaker. Precise systematic affinities of this new arthropod could not be determined. This discovery supports the conclusion that the tracemakers of various Arthrophycus ichnospecies are likely poorly preserved, and presently unknown, members of the Ecdysozoa.
A new early Danian gastropod assemblage contained in the Roca Formation of Río Negro Province was analyzed. Eleven species are described and illustrated, the new genus Rocalaria is created, and six new species are recognized: Gyroscala daniana, Heteroterma carmeloi, Microfulgur concheyroae, Sulcobuccinum prominentum, Cidarina lenzaniyeuensis, and Rocalaria alani. The present research includes the first mention of Sulcobuccinum d'Orbigny, 1850, Priscoficus Conrad, 1866, Cavoscala Whitfield, 1892, Microfulgur Finlay and Marwick, 1937, and Cidarina Dall, 1909, for the Danian of Southern South America; the new record of Austrophaera Furque and Camacho, 1949, Fusinus Rafinesque, 1815 and Heteroterma Gabb, 1869 in northern Patagonia; and the oldest Paleogene record for the genus Gyroscala de Boury, 1887. The presence of the study assemblage in northern Patagonia indicates a more complex paleobiogeographic pattern for the area than previously thought, as shown by the record of endemic genera, cosmopolitan taxa, elements with Tethyan/ Indo-Pacific affinities, and genera related with “Wangaloan” faunas of the Paleocene of New Zealand.
A very early juvenile specimen of Hypselocrinus hoveyi with arms and partial column attached is utilized to examine the growth in this Mississippian advanced cladid crinoid. The aboral cup height of this specimen is 4 mm. In contrast to results reported in previous studies of crinoids, Hypselocrinus hoveyi grew with a combination of allometric and isometric growth. Different plates of the aboral cup grew with a combination of growth modes, and arms grew with allometric growth or relative change in shape that was not strict allometry.
A new species of the Pliocene–Pleistocene flat-headed peccary, Platygonus pollenae, has been recovered latest Hemphillian (latest Miocene) localities from Nebraska, Kansas, Colorado, and Texas. It can be distinguished from other tayassuids by its distally rounded wing-like zygomatic process, and its subzygodont cheek teeth. In contrast to more derived species of Platygonus, it is much smaller in size, its molars are relatively more bunodont, the talon and talonid cusps are retained on the premolars of most individuals, and the mandibular symphysis lacks a median keel on the chin. In these characters, it is the earliest and the most primitive species of Platygonus known. It is more primitive than the typical Blancan species, or any of the species from the Pleistocene, and demonstrates the origin of this important Pleistocene mammal in the latest Miocene.
Proetid trilobites of Lower Devonian (Pragian) age are known principally from fragmentary material from the type area in the Czech Republic and Morocco. We describe well-preserved, articulated specimens from the Ihandar Formation of the Anti-Atlas, Morocco, which include species of previously little known genera, and help to clarify their morphology. Eight new species are described: Dalejeproetus sagaouii, D. owensi, Lepidoproetus maharchianus, L. lahceni, L. splendens, Podoliproetus mirdani, P. sinespina, and Proetina ihamadii.
A new species of Apiocrinites is described from the Middle Jurassic (Callovian) Matmor Formation of the Negev, Israel. Apiocrinites negevensis is from the tropical latitudes in the Tethys, in contrast to all other reported species of this genus. With a narrow radial facet and adjacent arms not in lateral contact and large aboral cup plates, A. negevensis is quite unusual for this genus.