Re: BIG MAMMAL TRAMPLES DEAD DINOSAUR! :-o

["dinotracker" <dinotracker@earthlink.net>]

David Marjanovic asked an important question:

    >Any chance it's the left side, and that the "thumb" is an offset digit
5
like seen in *Jeholodens*, so the animal could be something like the
gigantic *Repenomamus*? *Gobiconodon* had an Asiamerican distribution, so
maybe the closely related and coeval *R.* shared this.<

    A good question, so, I went back, looked closely, and compared the track
to what is known of the manus and pes of the Eutriconodont, Jeholodens.

    The footprint has very little resemblance to manus of the Jeholodens.
The Jeholodens manus is substantially more narrow than the imprint found on
June 17, and the track's seeming digit I is far more offset than is digit I
in Jeholodens.  Incidentally, it is digit I, not digit V, that is somewhat
offset in the Jeholodens manus.  As to the pes of Jeholodens, judging from
Ji, et al, (Nature 416, 25 April, 2002,The earliest eutherian mammal, fourth
page), the metatarsals are known, but not the tarsals, and I would guess,
looking at the metatarsals, that neither digit I nor digit V would be very
offset.

    Let me explain that the thing I called an imprint of digit I extends to
the left, off the proximal end of the foot print, well separated from the
other four digits.  It is slightly curved and juts out at roughly a 31
degree angle to the digit II impression!

    In my original posting on the large mammal track, I stated the length as
6.4 cm, but that includes 4 mm of what may be hair or fur marks behind the
'heel' (or slide-in marks, or ?), so the actual footprint without that is
6.0 cm.  I forgot to state the width, as measured via a line drawn from the
tip of digit I to the far right side of the foot print, which is 3.9 cm.

    Thanks to David for that potentially inquiry.

    Ray Stanford

"You know my method.  It is founded upon the observance of trifles." --
Sherlock Holmes in The Boscombe Valley Mystery

----- Original Message -----
From: "David Marjanovic" <david.marjanovic@gmx.at>
To: "The Dinosaur Mailing List" <dinosaur@usc.edu>
Sent: Wednesday, June 26, 2002 2:03 PM
Subject: Re: BIG MAMMAL TRAMPLES DEAD DINOSAUR! :-o


----- Original Message -----
From: "dinotracker" <dinotracker@earthlink.net>
To: "Dinosaur Mailing List" <dinosaur@usc.edu>
Sent: Wednesday, June 26, 2002 3:17 AM
Subject: BIG MAMMAL TRAMPLES DEAD DINOSAUR! :-o


> The track's digit I
> impression closely resembles what might be produced by an opposable (or
> quasi-opposable) thumb, making me wonder if it could be the track of a
very
> early marsupial.
> [...]
> Whether by pes or manus, the track surely was made by the right side of
the
> animal.

Any chance it's the left side, and that the "thumb" is an offset digit 5
like seen in *Jeholodens*, so the animal could be something like the
gigantic *Repenomamus*? *Gobiconodon* had an Asiamerican distribution, so
maybe the closely related and coeval *R.* shared this.