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In tetrapods, a mostly terrestrial clade evolved from lobe-finned fish, many pharyngeal arch elements are lost, including the gill arches. In amphibians and reptiles , only the oral jaws and a hyoid apparatus remains, and in mammals and birds the hyoid is simplified further to support the tongue and floor of the mouth .
With the placement of hemichordates and echinoderms as a sister group to chordates, a new hypothesis has emerged-suggesting that pharyngeal gill slits were present in the deuterostome ancestor . [11] Intriguingly, extant echinoderms lack pharyngeal structures, but fossil records reveal that ancestral forms of echinoderms had gill-like ...
Metaspriggina fossil from the Royal Ontario Museum's collection. Metaspriggina Walcotti is fish-like and measures up to 6 centimetres (2.4 in) in length and 1 centimetre (0.39 in) in breadth. [26] It possesses a notochord along with seven pairs of pharyngeal bars, possibly made of cartilage. The pharyngeal bars were formed of multiple separate ...
The history of the camel provides an example of how fossil evidence can be used to reconstruct migration and subsequent evolution. The fossil record indicates that the evolution of camelids started in North America (see figure 4e), from which, six million years ago, they migrated across the Bering Strait into Asia and then to Africa, and 3.5 ...
The pharyngeal jaws of most fishes are not mobile. The pharyngeal jaws of the moray are highly mobile, perhaps as an adaptation to the constricted nature of the burrows they inhabit which inhibits their ability to swallow as other fishes do by creating a negative pressure in the mouth. Instead, when the moray bites prey, it first bites normally ...
The human fossils found in the layers of sediment were originally difficult to date. Between Laotian laws protecting the remains and contaminating charcoal that had washed into the cave, several ...
Paleontologists at work at the dinosaur site of Lo Hueco (Cuenca, Spain). Vertebrate paleontology is the subfield of paleontology that seeks to discover, through the study of fossilized remains, the behavior, reproduction and appearance of extinct vertebrates (animals with vertebrae and their descendants).
Then, some scant but highly informative fossil evidence assigned to this family: a premaxillary tooth was found in the Colombian Villavieja Formation [4] and dated to the Laventan age about 13.5-11.5 Mya, while some pharyngeal teeth and other jaw parts found near Cuenca, Ecuador in the Cuenca basin (a structural basin [5]) are