Search results
Results From The WOW.Com Content Network
After an analysis of new fossil material, the subgenera were elevated to the rank of genus, and three new genera were erected. [3] Most of the family's current diversity is found in temperate waters of the Northern Hemisphere .
The order is estimated to contain nearly 15,000 extant species in around 2,700 genera, with around 3,300 fossil species. [1] Nearly half of these species are crabs, with the shrimp (about 3,000 species) and Anomura including hermit crabs , king crabs , porcelain crabs , squat lobsters (about 2500 species) making up the bulk of the remainder. [ 1 ]
Notable fossils from this formation is the gastropod Turritella, the bivalve Pterotrigonia thoracica (the state fossil of Tennessee), as well as other fossils such as crabs. It is alternately considered its own geologic formation (as the Coon Creek Formation) or a distinct member of the wider Ripley Formation (as the Coon Creek Member or the ...
Dakoticancroidea is a superfamily of fossil crabs divided into the following two families: [1] [2] [3] † Dakoticancridae Rathbun, 1917 † Avitelmessus Rathbun, 1923 † Dakoticancer Rathbun, 1917 † Tetracarcinus Weller, 1905 † Ibericancridae Artal, Guinot, Van Bakel & Castillo, 2008 † Ibericancer Artal, Guinot, Van Bakel & Castillo, 2008
Potamonautes lirrangensis, the Malawi blue crab, [2] is a species of freshwater crab in the family Potamonautidae. This common and widespread species is found in Lake Malawi , Lake Kivu , the upper Congo River Basin and Malagarasi River in the Democratic Republic of the Congo , Malawi , Rwanda , and Tanzania . [ 1 ]
Fossils are rarely preserved in tropical settings in comparison to other parts of the world, making this fossil an even more unusual discovery. [7] An in-depth study of the crab's eyes indicated that Callichimaera was an active predator living high in the water column .
The oldest known true crabs are Eoprosopon klugi and Eocarcinus praecursor from the Early to Middle Jurassic. [5] [6] While that fossil crab, and a few other Jurassic species, establish that crabs existed in older time periods, crabs did not truly diversify into numerous species until the beginning of the Cretaceous. [3]
Coeloma is an extinct genus of crabs belonging to the family Mathildellidae. The genus includes 19 species, [ 2 ] distributed among several subgenera, and is in need of revision. [ 1 ] The fossil record of the genus extends from the Eocene to the Miocene .