Re: Mesonychids to Whales

GRMorton@aol.com
Tue, 27 Jun 1995 07:34:12 -0400

Ashby wrote:
>As one who prides himself on caring only
>about the data, it seems you want to go beyond it to assume that
>certain creatures lived before there is any evidence of their
>existence. If you can assume, for example, that the genus
>_Mesonyx_ lived long before there is any fossil evidence of it,
>what is to prevent me from assuming that its alleged descendant is
>even older? Two can play that game. If we are not limited by the
>data in our analysis, it's a free-for-all.

The problem is statistical. Any object you find which becomes the earliest
occurrence is usually way, way before the previous earliest occurrence. I
have collected a bunch of examples.

earliest life on land
1.2 billion year old hollow filaments Arizona-oldest
800 MYR hollow filaments California
Horodyski and Knauath Life on Land in the Precambrian Science Jan 28, 1994 p
173

Caecilian bones
earliest 175-180 MYR
second 100 MYR
Farish A. Jenkins and Denis M. Walsh "Rare Fossils of Enigmatic Amphibian"
Science News 138 Oct 27, 1990 p. 270

tetrapods
Obruchavichthyid 368 MYR
Acanthostega Tulerpeton Ichthyostega 363 MYR
Amniator Crassigyrinus and a bunch of others 340 MYR
Ahlberg and Milner The origin and Early Diversification of Tetrapods Nature
Apr 7, 1994, p. 507

Dinosaurs
oldest 240 MYR tracks from France
Oldest fossil 228 MYR from South America
turkey sized dinosaur tracks Ft Wingate fm New Mexico 225 (Oldest on North
America)
200 mry track from North carolina (second oldest on North america)

Matt Crenson "Geologists report oldest sign of Dinosaurs in NOrth America
Dallas Morning News, May 9, 1994, p. 8d

tarsiers
oldest Eocene from China
second oldest early miocene 30 million years later

oldest turtle 60 million years earlier than the previously earliest turtle
Eugene S. Gaffney Jame W. Kitching The Most Ancient African Turtle Nature May
5, 1994, p. 55

birds Archaeopteryx 147 myr
sinornis santensis 139 mil
Las Hoyas bird 132 myr
ambiortus dementjevi 125 myr
Paul C. Sereno Rao Chenggang Early evolution of Avian Flight and perching
Science feb 14 1992 p. 845

Oldest maya farming 4500 yr
second oldest Maya farming 3000 year
B. Bower Maya beginnings extend back at Belize site, jScience News, April 30,
1994

Since earliest examples of everything are always being found, it is highly
unlikely that we ever have found the very earliest example of anything.
Recently there was a case of finding the earliest evidence of weaving at
80,000 years I beleive. Previously the earliest had been 19,000 I think. I
don't have time to find that reference. So today's earliest Mesonychid is
unlikely to be the actual earliest.

glenn