Search results
Results From The WOW.Com Content Network
Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates, including humans. Most gnathostomes have retained ancestral traits like true teeth , a stomach , [ 2 ] and paired appendages (pectoral and pelvic fins, arms, legs, wings, etc.). [ 3 ]
Acanthodii or acanthodians is an extinct class of gnathostomes (jawed fishes).They are currently considered to represent a paraphyletic grade of various fish lineages basal to extant Chondrichthyes, which includes living sharks, rays, and chimaeras.
It has a pair of cuticular jaws, supplied by strong muscles, and often bearing minute teeth. A "basal plate" on the lower surface that bears a comb-like structure is also present. The basal plate is used to scrape smaller organisms off of the grains of sand that make up their anoxic seabed mud habitat. [ 4 ]
For premium support please call: 800-290-4726 more ways to reach us
For premium support please call: 800-290-4726 more ways to reach us
The earliest deposited generations of accessory teeth in each row are located at the tip of the whorl spiral labially of the primary teeth. Unlike the continuously shedding teeth of modern sharks, [7] the tooth whorls of Qianodus retained their teeth and grew in size throughout the life of the animal. The recorded gradual enlargement of the ...
Using three tests, researchers determined that the 780,000-year-old bones indicated that humans cooked fish before eating it, according to the study. This marks the earliest evidence that hominins ...
The Cerutti Mastodon site (SDNHM locality 3767) is a paleontological site located in San Diego County, California, United States.A team of researchers from the San Diego Natural History Museum, led by Thomas Deméré, excavated the site from 1992 to 1993.