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Some help would be appreciated from anyone
with knowledge of a large and seemingly wading type bird (or if you prefer,
avian dinosaur) from the Early Cretaceous (late Barremian through early Aptian,
probably), which could produce a footprint 16 cm long (about 6.5 inches) from
tip of retroverted digit I to tip of digit III, and measuring 15.5 cm
(about 6.25 inches) across from the tip of digit II to the tip of digit IV, with
an angle of divarication between those two digits of 140 degrees (angle is
approximately the same as that in 'type C' bird tracks from the much younger
Green River formation). Unlike what is seen in those smaller 'type
C' bird prints of the Green River formation, digits I and III
appear to lie within a single posterior-anterior line.
The co-linear digits I and III strike me as
(theoretically) highly derived condition [Is that the right word?] to be found
in the Early Cretaceous according to many if not most current evolutionary
paradigms as I understand them. (Please keep in mind that I'm only an
amateur and certainly could be mistaken in suspecting that this would be
surprisingly early for such a degree of digit I - digit III alignment.)
In case there is any question, this query does not
concern a hypothetical track, but one that has been examined and measured.
Unless you think your information would be of interest
to other on this list, you may choose to respond privately.
Thanks for any help or insight,
Ray Stanford
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