Search results
Results From The WOW.Com Content Network
Exactly why the trilobites became extinct is not clear; with repeated extinction events (often followed by apparent recovery) throughout the trilobite fossil record, a combination of causes is likely. After the extinction event at the end of the Devonian period, what trilobite diversity remained was bottlenecked into the order Proetida.
Weymouthia is an extinct genus of eodiscinid agnostid trilobites which lived at the end of the Lower Cambrian. Its fossils are found in Lower Cambrian marine strata from what are now the eastern United States, England, Siberia and China.
Asaphellus is an extinct genus of trilobites reported from the Ordovician. It is seen in Argentina, Bolivia, Mexico, America, Algeria, Iran, Spain, Portugal, France, Great Britain, Czech Republic, Norway, Sweden and China. [1] [2] [3]
Most trilobites with this life history strategy lived in warm, low latitude waters, in which planktonic, non-adult like larvae may be ideal at surviving in. During the Ordovician-Silurian extinction event, the widespread onset of cold water conditions and anoxia may have instead favoured species that produced small numbers of large eggs, from ...
The cryptostome and trepostome bryozoans also became extinct at this time despite their long history of diversity and abundance earlier in the Paleozoic. Brachiopods suffered greatly and never regained their previous numbers or variety. Ammonoids lost all but one family. Eurypterids and trilobites became extinct. Blastoids became extinct.
Despite the world's last captive thylacine dying in 1936, the secretive animal wasn't declared extinct until 1986. More recently in 2007 the Baiji dolphin , a rare river dolphin native to China ...
Calymene Brongniart, 1822, is a genus of trilobites in the order Phacopida, suborder Calymenina, that are found throughout North America, North Africa, and Europe in primarily Silurian outcrops. [2] Calymene is closely related to Flexicalymene, and both genera are frequently found enrolled. [3] Calymene trilobites are small, typically 2 cm in ...
Trimerus is an extinct genus of trilobite in the family Homalonotidae. Trimerus is one of North America's largest trilobites, reaching over 20 cm (7.9 in) in length. It had a thorax composed of 13 segments with weak trilobation, a large subtriangular head terminating in an expanded rostral plate, a two-pronged hypostome , and a triangular ...