Megamouth Shark Morphometrics
Krak and Shimada use geometric morphometrics to reconstruct extinct megamouth shark tooth rows
Allonia from the middle Cambrian Wheeler Formation of Utah
Foster, Howells and Sroka report new details of early sponge-like animals from a spectacularly-preserved specimen from the Cambrian of western Utah.
Death Valley Devonian Acanthodians
A new stem chondrichthyan fauna from the Lost Burro Formation of California by Carole J. Burrow and David K. Elliot.
Toxochelys latiremis Cope, 1873
First report of this turtle from the Cretaceous of Alabama, USA by Andrew Gentry and Jun Ebersole.
Calliovarica oregonensis Hickman
A new species of chilodontid gastropod from the Eocene of Oregon, USA by Carole S. Hickman.
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.
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!
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.
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.
New report of the fossil otolith species, Equetulus silveraldensis n. comb., from the Oligocene of the Gulf Coastal Plain, USA!
Stringer et al. describe the first record of the teleostean fish otolith, Equetulus silveraldensis n. comb., from the Oligocene of Alabama, USA, and its enigmatic geographic distribution.
New dinosauromorph body fossils from the Petrified Forest National Park, Arizona, USA!
Adam Marsh and William Parker describe new dinosauromorph specimens from the Chinle Formation Petrified Forest National Park and provide a global biostratigraphic review of Triassic dinosauromorphs.
Checklist of Paleogene-Neogene marine Mollusca from California!
Groves and Squires present an annotated catalog of Paleogene-Neogene Mollusca from California since Keen and Bentson's 1944 checklist.
New mid-Miocene equids from the Cajon Valley Formation, CA!
Stoneburg et al. describe new fossil horse remains from the mid-Miocene of San Bernardino County, CA.
New fossil fishes from South Carolina, USA!
Cicimurri et al. report on a diverse fauna of Oligocene fishes from the Ashley Formation of South Carolina, with description of a new catshark species, Scyliorhinus weemsi.
Changes in southern California oyster paleocommunity structure over the last 3.6 million years!
Bonuso et al. use digitized data from the EPICC TCN and other sources to reconstruct Late Cenozoic oyster communities in southern California, USA.
The earliest Ancistrolepis, from the early Eocene of Simi Valley, California, USA
Squires updates our knowledge of the oldest species of this extant buccinid gastropod genus
The first Cretaceous fish otolith assemblage from the Arkadelphia Formation of Arkansas, USA!
Stringer and Sloan describe the first otolith assemblage from the Late Cretaceous of Arkansas and its implications for our understanding of the Western Interior Seaway.
Pteriomorph bivalves from the Eocene-Oligocene Keasey Formation in Oregon, USA!
Hickman describes the pteriomorph bivalves from the Eocene-early Oligocene Keasey Formation in Oregon, recognizing a new peri-seep biotope association.
Volume 42, Issue 1, 2025
42
Articles
Multiple geniculated types in a single inoceramid (Bivalvia) species: “Inoceramus” nebrascensis
ABSTRACT Inoceramids have been studied extensively over the last 200 years and, along with ammonites, have become an important tool for Late Cretaceous biostratigraphy. Geniculation, the abrupt change in convexity/inflation of the valve disc, occurs in many inoceramids and has been recognized for decades. But despite extensive inoceramid research, it remains a relatively under-documented phenomenon. To understand the phylogenetic relationships within this cosmopolitan bivalve family, it is necessary to recognize the range of intraspecies variation. “ Inoceramus ” nebrascensis is known to geniculate, but its morphological variability has not been effectively documented. This study identifies five morphotypes of “I.” nebrascensis from a single locality of the Late Campanian Pierre Shale in South Dakota. The most common form is non-geniculated (Type I). The four geniculated forms include: marked positive geniculation (Type II); slight positive geniculation followed promptly by marked negative geniculation (Type III); marked positive geniculation generating a conspicuous neck, followed by marked negative geniculation (Type IV); extreme positive geniculation with a “butterflied” configuration of the pre-adult shell (Type V). This study also argues for a three-stage shell development for this species (juvenile, intermediate, and adult) rather than the two stages described in previous studies.