Re: More on the Massospondylus embryos

["Jaime A. Headden" <qilongia@yahoo.com>]

"Jura" Jason (pristichampsus@yahoo.com) wrote:

<Alternatively, one could posit that the teeth came in later, and that the
young just lived off their yolk until then. Personally, I don't really see that
as being very viable. Extant animals that rely on their yolk sacs for
nourishment in the first couple of days of life, still have functional teeth in
place.>

  The authors note that the jaws possess open alveoli and at least one tooth is
suggested as an erupted, but loose, crown. I previously mentioned a possible
loose tooth in one skeleton, whereas the authors refer to another jaw. This
suggests the animals hatched with teeth. Lack of epiphyseal fusion, carpal or
tarsal ossification, suggests the hatchlings were altricial, and a supposedly
hatched egg in the hatch of 6 suggests the nest was close to fully hatching,
thus implying parental care for some period of time.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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