Re: aquatic equus?

Holly Reeser (
Tue, 27 Aug 1996 19:46:56 -0400

Phillip Bigelow wrote:
> Holly Reeser wrote:
> >
> > I am currently working from fossils from Leisey Shell Pit. In broad
> > strokes....if I was assuming that finding fossils in an aquatice context
> > presupposes that they were themselves aquatically adapted then my Equus
> > fossils must represent a period in the evolution of the horse when they
> > were too aquatic since their remains were found in association with
> > marine organisms deposited in a shallow embayment. Eureka it is a
> > breakthrough!
> <Sarcasm mode on>
> Oh yes indeed! There is even more evidence for an aquatic past for equus:
> keep in mind that horses love the water, and horses are often seen
> running on the ocean beaches. (That's Morgan-esque evidence).
> Cows, on the other hand, do not like the water, and are not seen
> running on the ocean beaches. There you go. It's a lock. Cows evolved on
> land, and horses had a past aquatic phase.
> <Sarcasm mode off>
> Seriously,
> At a recent S.V.P. conference, a paleontologist from Idaho (G. McDonald)
> and a co-author reported that they had evidence for an "aquatic" sloth
> from the Pliocene of South America.
> Their evidence for aquaticness in this animal is at odds with the so-
> called "evidence" that Hardy and Morgan use to infer aquaticness in
> their purported hominid ancestor.
> One of the pieces of evidence that McDonald used was the depositional
> environment of the site. But, more importantly, he cited a short list
> of morphologic features that, in my opinion, carry more weight than the
> dep.env. evidence.
> Anyone who has spent ANY amount of time working with marine rocks
> knows how much terrestrial material is usually incorporated in the
> unit.
> In my area of knowledge (Tert. marine rocks of the Pac. NW.), I
> personally am aware of a gomphothere skeleton (a mastodon-like animal)
> that was deposited near the very center of a large Miocene marine
> embayment. I also know of many examples of dinosaur skeletons (terrestrial
> creatures) that were found in the marine Bearpaw Shale of the
> Western Interior.
> In my opinion, the depositional environment is the least important
> piece of evidence that should be used to determine the niche of an
> exinct animal. In fact, it has a strong tendency to lead one down
> the wrong path.
> <pb>

Exactly my point....Leisey Shell Pit's depostional environment was a
shallow marine embayment.....we have a huge sample of terrestrial
vertebrates 203 species .... all aquatic because they were found within a
shell bed? No way!