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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 ...
Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship lines within the family Hominidae, working from biological evidence (such as petrified skeletal remains, bone fragments, footprints) and cultural ...
A study on the anatomy and affinities of Lasanius is published by Reeves et al. (2023), who interpret this vertebrate as a stem-cyclostome. [9]Dearden et al. (2023) describe the cranial anatomy of Eriptychius americanus, provide evidence of the presence of a symmetrical set of cartilages interpreted as the preorbital neurocranium, and report that the studied cartilages filled out the head and ...
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 .
Metaspriggina also possessed a notochord, along with seven pairs of pharyngeal bars, possibly made of cartilage. Surprisingly they were not formed from a singular bone, but they were formed of multiple separate pairs of bones, along with first two of them that were enlarged compared to the others and that seemed to not support any gills, all of ...
While there is no fossil evidence directly to support this theory, it makes sense in light of the numbers of pharyngeal arches that are visible in extant jawed vertebrates (the Gnathostomes), which have seven arches, and primitive jawless vertebrates (the Agnatha), which have nine.
Kenyapithecus wickeri is a fossil ape discovered by Louis Leakey in 1961 at a site called Fort Ternan in Kenya.The upper jaw and teeth were dated to 14 million years ago. [2] One theory states that Kenyapithecus may be the common ancestor of all the great apes.
Extraordinary evidence of internal fertilization in a placoderm was afforded by the discovery in the Gogo Formation, near Fitzroy Crossing, Kimberley, Western Australia, [11] of a small female placoderm, about 25 cm (10 in) in length, which died in the process of giving birth to a 6 cm (2 + 1 ⁄ 2 in) offspring and was fossilized with the ...