Terrestrial Vertebrate Assemblages Research Articles

Depositional environments of a Middle Jurassic terrestrial vertebrate assemblage, Huizachal Canyon, Mexico

ABSTRACT A large assemblage of vertebrate fossils from the La Boca Formation in Huizachal Canyon, near Ciudad Victoria, Tamaulipas, Mexico, is preserved in a unique setting: debris-flow sediments deposited over a landscape with at least modest topographic relief. Angular feldspar lathes in the rock suggest that deposition was associated with penecontemporaneous volcanism. The ~8,000-specimen collection from Huizachal Canyon includes the tritylodontid Bocatherium mexicanum, the burrowing diapsid Tamaulipasaurus morenoi, three types of mammals, two crocodyliforms, two types of dinosaurs, a pterosaur, and three sphenodontians. The fossils generally occur as small (~5 mm), isolated bones or bone fragments, but 35 articulated or associated specimens have been found. No turtles or fishes have been identified, implying a terrestrial source for this assemblage. Biostratigraphic and preliminary radiometric evidence suggest an early Middle Jurassic age, making this assemblage the only substantial terrestrial Middle...

Lepidosauromorph reptiles from the Middle Jurassic of Skye

Abstract The Middle Jurassic Kilmaluag Formation (previously known as the Ostracod Limestones) of the Great Estuarine Group in Skye, Scotland, has yielded an assemblage of Bathonian terrestrial vertebrates including mammals, tritylodonts, crocodiles and turtles. This paper presents the first description of Jurassic lepidosauromorph reptiles from Scotland. Two genera are represented: a crown-group lizard referable to the late jurassic/early Cretaceous genus Paramacellodus (Squamata: Scincomorpha) and a stem-group lepidosauromorph, Marmoretta Evans, 1991, first described from the late Bathonian of Kirtlington, Oxfordshire. The Skye material of Marmoretta includes the first associated skull and postcranial remains. These confirm the original description and reconstruction, and provide further support for a hypothesis of relationship which places Marmoretta as the sister taxon of Lepidosauria.

Lepidosauromorph reptiles from the Middle Jurassic of Skye

The Middle Jurassic Kilmaluag Formation (previously known as the Ostracod Limestones) of the Great Estuarine Group in Skye, Scotland, has yielded an assemblage of Bathonian terrestrial vertebrates including mammals, tritylodonts, crocodiles and turtles. This paper presents the first description of Jurassic lepidosauromorph reptiles from Scotland. Two genera are represented: a crown-group lizard referable to the late jurassic/early Cretaceous genus Paramacellodus (Squamata: Scincomorpha) and a stem-group lepidosauromorph, Marmoretta Evans, 1991, first described from the late Bathonian of Kirtlington, Oxfordshire. The Skye material of Marmoretta includes the first associated skull and postcranial remains. These confirm the original description and reconstruction, and provide further support for a hypothesis of relationship which places Marmoretta as the sister taxon of Lepidosauria.

沖縄県普天満宮遺跡における陸生脊椎動物遺骸群

A new fossil assemblage of terrestrial vertebrates was found from limestone breccias, forming a cave deposit in the Futenma-gu (Shrine) Cave, Ginowan City, Okinawa (long., 26°17′19.5″;lat., 127°46′44.2″).The site represents one of the well preserved and most fo ssiliferous localities of terrestrial vertebrates in Ryukyu Islands. The assemblage of the Futenmagu site consists of the following species. Mammalia: Cervus astylodon, Dicrocerus sp. and Chiroptera; Amphibia and Reptilia: Testudo sp. nov., Geoemyda spengleri japonica , Japalura sp. And there are a few species of Ayes. As the good majority of the fossil bones be-longs to deer, it was attempted to estimate the number of individuals of each species of the fossil deers by canine teeth and axes; minimum of 67 individuals of Cervus astylodon and 133of Dicrocerus sp. were counted. This assemblage records the first fossil locality of Geoemyda spengleri japonica in Okinawa-jima and an addition for Tesudo sp. nov. in Ryukyu Islands. The species composition of the Futenma-gu assemblage is characterized with the abundance of Cervus astylodon and Dicrocerus sp . and the lack of Sus sp. and Diplothrix legata, so that it is tentatively correlated with the Yamashita-cho Daiichi Cave assemblage (Naha, Okinawa) of 32, 000 ± 1, 000y.B.P.in radiocarbon age. It is suggested that fossil land tortoises were introduced into the Ryukyu Islands earlier than hitherto presumed.

Problems of Upper Permian and Triassic Stratigraphy on the Russian Platform, in the Light of Paleomagnetic, Paleontological and Lithostratigraphic Evidence [Abstract

Abstract Stratigraphic studies of reference sections of Upper Permian and Triassic red beds on the Russian Platform have led to the compilation of a detailed stratigraphic succession. At the same time paleontological work has revealed a vertical distribution of terrestrial vertebrate assemblages which closely corresponds with stages and substages and therefore has some biostratigraphic value. Detailed paleomagnetic studies of the Permian and Triassic red beds of the platform have indicated the presence of alternating normal and reversed magnetic episodes from which a standard paleomagnetic section has been compiled. This section may conveniently be correlated with the major subdivisions of the stratigraphic succession. Continental deposits of the Kazanian Stage are characterized by the Cis-Ural Deinocephalus assemblage, while the Lower Tatarian Substage is typified by the Isheev Deinocephalus assemblage. Paleomagnetic work reveals that the deposits of the Ufimian and Kazanian Stages, and the Lower Tatarian Sub-stage, collectively represent a single, continuous paleomagnetic unit of reversed polarity (R1P). The Upper Tatarian Substage is characterized by the Severodvinsk Pareiasaurus and the Gorki Batrachosaurus assemblages. Paleomagnetically, this substage is divided into four units: N1P, R1P, N2P and R2P. The unit R2P is not present in the Kazan region and in the sections exposed in the southern Urals. In the overlying Triassic deposits, the Lower Triassic section can be divided into four subdivisions based on alternations in paleomagnetic direction: N1T, R1T, N2T, and R2T. The Middle and Upper Triassic strata have normal magnetic fields and can provisionally be regarded as a single zone N3T (the Cis-Ural zone). Permian and Triassic deposits of the Russian Platform have long been considered a standard for correlation with synchronous rocks of other regions of the world. The relative distribution of normal and reversed magnetism in Permian and Triassic rocks on the platform is essentially the same as in North America, South Africa and Australia, thus demonstrating the objective value of paleomagnetic correlations. Boundaries of major zones, such as the R-Kiama-NR-Illawara zone and the NR-Illawara-N-Cis-Ural zone can therefore be regarded as reliable isochronous units of worldwide significance.

A "Permian" Flora from the Pennsylvanian Rocks of Kansas

Near Garnett, east-central Kansas, a thin shale that belongs near the top of the Lansing group, approximately in the middle part of the Kansas Pennsylvanian section, contains a remarkably well-preserved assemblage of land plants, terrestrial and aquatic vertebrates, and marine and terrestrial invertebrates. The flora is so strongly Permian in aspect that some paleobotanists conclude the containing beds must be of Permian age. Occurrence of a disconformity below the fossiliferous shale suggests to some students unfamiliar with the regional setting that the Garnett beds may actually be Permian, and that the apparent stratigraphic position in the Middle Pennsylvanian is due to overlap. An equally untenable hypothesis holds that the upper part of the section now classed as Pennsylvanian might be assigned to the Permian as customarily defined. This paper shows that the fossil-bearing shale is correctly placed in the Lansing group and does not represent a Permian overlap or local channel-filling. The characters of the biota are briefly described, and peculiarities of the flora are interpreted as due to environment factors. The flora is undeniably of "Permian" type, but lived in Pennsylvanian time.