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  2. Gnathostomata - Wikipedia

    en.wikipedia.org/wiki/Gnathostomata

    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 ]

  3. Acanthodii - Wikipedia

    en.wikipedia.org/wiki/Acanthodii

    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.

  4. Heslington Brain - Wikipedia

    en.wikipedia.org/wiki/Heslington_Brain

    The Heslington Brain is a 2,600-year-old human brain found inside a skull buried in a pit in Heslington, Yorkshire, in England, by York Archaeological Trust in 2008. It is the oldest preserved brain ever found in Eurasia , and is believed to be the best-preserved ancient brain in the world. [ 1 ]

  5. Echidna - Wikipedia

    en.wikipedia.org/wiki/Echidna

    The echidna's brain is half neocortex, [17] compared to 80% of a human brain. [18] [19] Contrary to previous research, the echidna does enter REM sleep, but only in a comfortable temperature around 25 °C (77 °F). At lower or higher temperatures of 15 °C (59 °F) and 28 °C (82 °F), REM sleep is suppressed. [20]

  6. Conodont - Wikipedia

    en.wikipedia.org/wiki/Conodont

    Conodont elements consist of mineralised teeth-like structures of varying morphology and complexity. The evolution of mineralized tissues has been puzzling for more than a century. It has been hypothesized that the first mechanism of chordate tissue mineralization began either in the oral skeleton of conodonts or the dermal skeleton of early ...

  7. Placoderm - Wikipedia

    en.wikipedia.org/wiki/Placoderm

    A study of the arthrodire Compagopiscis published in 2012 concluded that placoderms (at least this particular genus) likely possessed true teeth contrary to some early studies. The teeth had well defined pulp cavities and were made of both bone and dentine. However, the tooth and jaw development were not as closely integrated as in modern ...

  8. Tullimonstrum - Wikipedia

    en.wikipedia.org/wiki/Tullimonstrum

    The supposed brain has no associated nervous tissue and is not connected to the eyes, and the purported liver was located under the gills as opposed to being further back as in other vertebrates. The "mouth" at the front of the proboscis was described as possessing gnathostome -like distinct tooth rows, despite lampreys having "tooth fields" on ...

  9. List of human evolution fossils - Wikipedia

    en.wikipedia.org/wiki/List_of_human_evolution...

    The chimpanzee–human divergence likely took place during around 10 to 7 million years ago. [1] The list of fossils begins with Graecopithecus, dated some 7.2 million years ago, which may or may not still be ancestral to both the human and the chimpanzee lineage.