The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often considered a component of the more widespread Heath Formation. The Bear Gulch Limestone reconstructs a diverse, though isolated, marine ecosystem which developed near the end of the Serpukhovian age. It is a lagerstätte, a particular type of rock unit with exceptional fossil preservation of both articulated skeletons and soft tissues. Bear Gulch fossils include a variety of fish, invertebrates, and algae occupying a number of different habitats within a preserved shallow bay.
Falcatus is an extinct genus of falcatid chondrichthyan which lived during the early Carboniferous Period in Bear Gulch bay in what is now Montana.
Hapsidopareion is an extinct genus of microsaur belonging to the family Hapsidopareiidae. Fossils have been found in the early Permian of Oklahoma.
Aeschronectida is an extinct order of mantis shrimp-like crustaceans which lived in the Mississippian subperiod in what is now Montana. They exclusively lived in the Carboniferous, or the age of amphibians. They have been found mostly in the U.S. and in the British Isles, in 1979 species were found in the Madera Formation in New Mexico. Aeschronectida was first identified appearing in Continental Europe in around 2014. While sharing similar characteristics to Stomatopoda, they lack certain physical characteristics of that taxon. The first species of Aeschronectida is accredited to Frederick R. Schram. They diverge substantially from typical hoplocaridan morphology by having more unmodified thoracopods. It's theorized that these thoracopods evolved to become more specialized, making them potential ancestors to Stomatopoda.
The Marjum Formation is a Cambrian geological formation that overlies the Wheeler Shale in the House Range, Utah. It is named after its type locality, Marjum Pass, and was defined in 1908. The formation is known for its occasional preservation of soft-bodied tissue, and is slightly younger than the Burgess Shale, falling in the Ptychagnostus praecurrens trilobite zone.
Cyclida is an extinct order of crab-like fossil arthropods that lived from the Carboniferous to the Jurassic and possibly Cretaceous. Their classification is uncertain, but they are generally interpreted as crustaceans, likely belonging to the superclass Multicrustacea.
Stenopodidae is a family of decapods in the order Decapoda, sometimes known as boxer shrimp. There are about 6 genera and more than 30 described species in Stenopodidae. The oldest record of the family dates to the Devonian.
Paleontology in Oklahoma refers to paleontological research occurring within or conducted by people from the U.S. state of Oklahoma. Oklahoma has a rich fossil record spanning all three eras of the Phanerozoic Eon. Oklahoma is the best source of Pennsylvanian fossils in the United States due to having an exceptionally complete geologic record of the epoch. From the Cambrian to the Devonian, all of Oklahoma was covered by a sea that would come to be home to creatures like brachiopods, bryozoans, graptolites and trilobites. During the Carboniferous, an expanse of coastal deltaic swamps formed in areas of the state where early tetrapods would leave behind footprints that would later fossilize. The sea withdrew altogether during the Permian period. Oklahoma was home a variety of insects as well as early amphibians and reptiles. Oklahoma stayed dry for most of the Mesozoic. During the Late Triassic, carnivorous dinosaurs left behind footprints that would later fossilize. During the Cretaceous, however, the state was mostly covered by the Western Interior Seaway, which was home to huge ammonites and other marine invertebrates. During the Cenozoic, Oklahoma became home to creatures like bison, camels, creodonts, and horses. During the Ice Age, the state was home to mammoths and mastodons. Local Native Americans are known to have used fossils for medicinal purposes. The Jurassic dinosaur Saurophaganax maximus is the Oklahoma state fossil.
Archipolypoda is an extinct group of millipedes known from fossils in Europe and North America and containing the earliest known land animals. The Archipolypoda was erected by Scudder (1882) but redefined in 2005 with the description of several new species from Scotland. Distinguishing characteristics include relatively large eyes with densely packed ocelli, and modified leg pairs on the 8th body ring. Some species had prominent spines while others had a flattened appearance.
The Ash Hollow Formation of the Ogallala Group is a geological formation found in Nebraska and South Dakota. It preserves fossils dating back to the Neogene period. It was named after Ash Hollow, Nebraska and can be seen in Ash Hollow State Historical Park. Ashfall Fossil Beds State Historical Park is within this formation.
This timeline of eurypterid research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of eurypterids, a group of extinct aquatic arthropods closely related to modern arachnids and horseshoe crabs that lived during the Paleozoic Era.
Diaphragmus is an extinct genus of brachiopod belonging to the order Productida and family Linoproductidae. Specimens have been found in Carboniferous beds in North America.
Pulchratia is an extinct genus of brachiopods which lived in marine habitats during the Upper Carboniferous period. Its fossils have been found in North America.
Tyrannosculda is an extinct genus of mantis shrimp which lived during the Late Jurassic in southern Germany. It was named in 2021, with T. laurae as the type and only species. Several fossil specimens are known, representing various growth stages.
Tyrannophontes is an extinct genus of mantis shrimp that lived during the late Carboniferous period in what is now the Mazon Creek fossil beds of Illinois. It is the only genus in the family Tyrannophontidae. The type species, T. theridion, was described in 1969 by Frederick Schram. A second, much larger species, T. gigantion, was also named by Schram in 2007. Another species, T. acanthocercus from the Bear Gulch Limestone of Montana, was formerly assigned to Tyrannophontes, but has now been moved to the genus Daidal.
Daidal is an extinct genus of mantis shrimp that lived during the Carboniferous period. It is the only genus in the family Daidalidae. Three species are currently placed within the genus. Fossils of the type species, D. acanthocercus, have been found in the Bear Gulch Limestone of Montana. A second species, D. pattoni, is known from the Lower Limestone Formation of Scotland, and the third species, D. schoellmanni, was discovered in Westphalia, Germany. The genus has been proposed to be polyphyletic, with D. pattoni possibly being an earlier diverging lineage, though more specimens and research are needed to confirm this.
Gorgonophontes is an extinct genus of mantis shrimp that lived during the late Carboniferous period in what is now the United States and Belgium. It contains two named species. The type species, G. peleron, was described in 1984 by Frederick Schram based on 100 specimens found in Nebraska and Iowa. A second species, G. fraiponti, was first named from multiple specimens found near Liège in 1922 and later reassigned to the genus.
Chabardella is an extinct genus of mantis shrimp which lived during the Late Carboniferous in France. It was named in 2009, with C. spinosa as the type and only species.
Bairdops is an extinct genus of mantis shrimp that lived during the Early Carboniferous period in what is now Scotland and the United States. Two named species are currently assigned to it. The type species, B. elegans, has been collected from several Dinantian-aged localities in Scotland, and was first described in 1908 by British geologist Ben Peach as a species of Perimecturus. The generic name was coined decades later in 1979 by American paleontologist Frederick Schram, and honors William Baird. A later species, B. beargulchensis, was named in 1978 after the Serpukhovian-aged Bear Gulch Limestone of Montana where it was discovered. The two species were originally deemed close relatives based on their physical similarities, but several cladistic analyses published since 1998 have suggested the genus may be polyphyletic.
Perimecturus is an extinct genus of mantis shrimp that lived during the Early Carboniferous period in what is now Scotland and the United States. The first known specimens were collected near the River Esk in Glencartholm, Scotland, and the genus was named in 1908 by Ben Peach, making it the first genus of Paleozoic mantis shrimp to be described. While many species have been classified in the genus since then, taxonomic revisions in the late 20th and 21st centuries have reassigned most of these to different genera, leaving two named species currently assigned to this genus. The type species, P. parki, was first named in 1882 as a species of Anthrapalaemon and is known from the Viséan-aged Glencartholm Volcanic Beds of Scotland. Fossils of a later species, P. rapax, have been found in the Bear Gulch Limestone of Montana and were first described by Frederick Schram.
