Faunal change in Cretaceous endemic bivalves of the northeast Pacific!
Richard Squires reports on the faunal change in Cretaceous shallow-marine endemic bivalve genera/subgenera of the northeast Pacific region.
First leatherback sea turtle (family Dermochelyidae) from the Mio-Pliocene Purisima Formation of California!
Bailey Fallon and Bobby Boessenecker describe the first leatherback sea turtle, cf. Psephophorus, from the lower Pliocene Purisima Formation of California, USA.
The Miocene Mascall vertebrate fauna revisited!
An excellent update of the vertebrate fauna and chronostratigraphy of the Miocene type Mascall Formation, John Day Basin, Oregon, USA by Kaitlin Clare Maguire, Joshua Samuels, and Mark Schmitz.
Toxochelys latiremis Cope, 1873
First report of this turtle from the Cretaceous of Alabama, USA by Andrew Gentry and Jun Ebersole.
Program and abstracts for the 52nd annual meeting of the Western Association of Vertebrate Paleontologists held at Dixie State University in St. George, Utah, USA.
Calliovarica oregonensis Hickman
A new species of chilodontid gastropod from the Eocene of Oregon, USA by Carole S. Hickman.
Late Triassic vertebrates from the Dockum Group of Texas!
New apomorphy-based identifications of vertebrates from the Late Triassic Dockum Group of Texas by Lessner et al.
An EPICC contribution!
Annotated list of the Cenozoic marine formations of the Pacific Northwest by Liz Nesbitt.
Use of machine learning to classify extant apes!
Monson et al. apply machine learning using dental morphology to classify extant apes and shed light on the chimpanzee-human last common ancestor.
New subadult skull specimen of Euclastes wielandi Hay, 1908 from the Cretaceous of New Jersey, USA!
New study of a subadult skull by P. Ullmann, Z. Boles and M. Knell provides insights into the cranial morphology and intraspecific variation in the Cretaceous pan-cheloniid turtle Euclastes wielandi.
Cimolestids (Mammalia) from the Paleocene of Montana!
New report on Puercolestes and Betonnia, two cimolestids from the early Paleocene (Puercan) of northeastern Montana, U.S.A. by William A. Clemens.
Eocene cassid gastropods from North America!
A reassessment by Richard Squires of Eocene warm-water cassid gastropods (Family Cassidae) from North America and implications for their paleogeographic distribution and faunal turnover following the Paleocene-Eocene Thermal Maximum.
Late Eocene elasmobranchs from Aiken County, South Carolina, USA!
Cicimurri and Knight describe new material of sharks and rays (elasmobrachs) from the Dry Branch Formation of Aiken County, South Carolina USA.
NAPC 2019 Field trip guide to the Ediacaran-Cambrian transition in the southwestern USA!
Field trip guide to the Ediacaran-Cambrian transition led by E. Smith, L. Tarhan and L. Nelson for the 2019 North American Paleontological Convention (NAPC).
Late Cretaceous endemic shallow-marine gastropods of the northeast Pacific!
Biodiversity and faunal changes in Late Cretaceous northeast Pacific gastropods by Richard L. Squires.
NAPC 2019 field trip guide to the geology and paleontology of Miocene formations in southern California!
Katharine Loughney and Tara Smiley's NAPC 2019 field trip guide to the geology and paleontology of the Miocene Barstow, Crowder, and Cajon Valley formations of southern California.
Program and Abstracts for the 11th North American Paleontological Conference!
Program and Abstracts for the 11th North American Paleontological Conference (NAPC) hosted by University of California, Riverside June 23-27, 2019.
Nestling-sized hadrosaurine crania from the Late Cretaceous of Montana!
Wosik et al. describe new cranial remains of hadrosaurine nestlings from the Late Cretaceous Hell Creek Formation, Montana, USA, with analysis of cranial ontogeny in Edmontosaurus annectens.
Miocene macropaleontology of the Caldecott Tunnel fourth bore excavation, Berkeley Hills, CA, USA!
Powell et al. describe Miocene marine macrofossils recovered from the fourth bore excavation of the Caldecott Tunnel in the Berkeley Hills, Oakland, CA, USA.
New protocol for differentiating leporids from the late Quaternary of southern California, USA!
Fox et al. propose new protocol using dental morphology for identifying late Quaternary leporids from southern California with remarks on lagomorphs from Rancho La Brea's Project 23!
A new drepanosauromorph from the Chinle Formation of Petrified Forest National Park, Arizona, USA!
Gonçalves and Sidor describe the new Triassicdrepanosauromorph genus and species,Ancistronychus paradoxus, from the Chinle Formation of the Petrified Forest National Park, Arizona, USA!
New limpets from the Miocene of southern California, USA!
Charles Powell and Daniel Geiger describe and name two new limpet species, Scelidotoma aldersoni n. sp. and Fissurella? stantoni n. sp. from the Miocene of southern California, USA.
Epiplastral shape and geographic variation of Echmatemys from the Eocene of Utah!
Heather F. Smith et al. analyze epiplastral shape and geographic variation in thegeoemydid turtle, Echmatemys,from the Eocene Uinta Basin , Utah, USA.
The new species Lyropecten terrysmithae from the Miocene of central California!
Powell et al. describe and name a new pectinid, Lyropecten terrysmithae , from the Miocene of California in honor of Dr. Judy Terry Smith for her work on California and Mexican invertebrate paleontology.
Volume 30, Issue 3, 2014
Leidyosuchus (Crocodylia: Alligatoroidea) from the Upper Cretaceous Kaiparowits Formation (late Campanian) of Utah, USA
Several crocodyliform lineages inhabited the Western Interior Basin of North America during the late Campanian (Late Cretaceous), with alligatoroids in the Kaiparowits Formation of southern Utah exhibiting exceptional diversity within this setting. A partial skeleton of a previously unknown alligatoroid taxon from the Kaiparowits Formation may represent the fifth alligatoroid and sixth crocodyliform lineage from this unit. The fossil includes the lower jaw, numerous osteoderms, vertebrae, ribs, and a humerus. The lower jaw is generally long and slender, and the dentary features 22 alveoli with conical, non-globidont teeth. The splenial contributes to the posterior quarter of the mandibular symphysis, which extends posteriorly to the level of alveolus 8, and the dorsal process of the surangular is forked around the terminal alveolus. Dorsal midline osteoderms are square. This combination of character states identifies the Kaiparowits taxon as the sister taxon of the early alligatoroid Leidyosuchus canadensis from the Late Cretaceous of Alberta, the first verified report of the Leidyosuchus (sensu stricto) lineage from the southern Western Interior Basin. This phylogenetic placement is consistent with at least occasional faunal exchanges between northern and southern parts of the Western Interior Basin during the late Campanian, as noted for other reptile clades.
The extant genus Salix Linnaeus (1753) represents one of the most diverse groups of woody plants. Leaf areas vary from a few mm2 in arctic or high alpine habitats to more than 100 cm2 in humid subtropical zones. Salix leaves are represented across the range of possible leaf shapes, from circular, obovate, and ovate, to lanceolate and linear with a length-to-width ratio of up to 30. Leaf venation may be eucamptodromous, eucamptodromous with occasional brochidodromous or semicraspedodromous arches, or brochidodromous. Because brochidodromous and semicraspedodromous arches may occur on the same leaf, the more inclusive term brochoid is introduced here. This study gives an overview of venation patterns within extant genus Salix and sorts leaves into five venation-defined morphotype groups. In some species of subgenera Protitea and Salix, individuals in hot, dry environments develop long brochoid chains over most of the blade length or intramarginal veins with only tertiary-gauged connections to the secondary vein framework. These unusual venation patterns correlate with high mean monthly temperature (MMT) and low mean monthly precipitation (MMP) of the hottest month. This study also discusses possible reasons as to why intramarginal veins seem to be absent or at least rare in fossil Salix specimens. These findings aid in both distinguishing between fossil Salix species and in separating fossil Salix remains from those of other genera.
One of the iconic fossils of the John Day Fossil Beds National Monument, Oregon, USA, is the Hancock Tree—a permineralized standing tree stump about 0.5 m in diameter and 2.5 m in height, embedded in a lahar of the Clarno Formation of middle Eocene age. We examined the wood anatomy of this stump, together with other permineralized woods and leaf impressions from the same stratigraphic level, to gain an understanding of the vegetation intercepted by the lahar. Wood of the Hancock Tree is characterized by narrow and numerous vessels, exclusively scalariform perforation plates, exclusively uniseriate rays, and diffuse axial parenchyma. These features and the type of vessel-ray parenchyma indicate affinities with the Hamamelidaceae, with closest similarity to the Exbucklandoideae, which is today native to Southeast and East Asia. The Hancock Tree is but one of at least 48 trees entombed in the same mudflow; 14 others have anatomy similar to the Hancock Tree; 20 have anatomy similar to Platanoxylon haydenii (Platanaceae), two resemble Scottoxylon eocenicum (probably in order Urticales). The latter two wood types occur in the nearby Clarno Nut Beds. Two others are distinct types of dicots, one with features seen in the Juglandaceae, the other of unknown affinities, and the rest are very poorly preserved and of unknown affinity. Leaf impressions in and immediately below the layer containing the trees include the extinct genera Macginitiea and Platimeliphyllum (Platanaceae), and Trochodendroides (Saxifragales).