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Study suggests macroscopic bilaterian animals did not appear until 555 million years ago
University of California, Riverside, UCR News ^
| September 26, 2002
| Dr. Mary Droser
Posted on 09/30/2002 7:03:42 AM PDT by forsnax5
RIVERSIDE, Calif. -- The traces left behind by ancient animals may hold the key to determining when macroscopic bilaterians -- animals that are symmetric about a central axis, with a body divided into equivalent right and left halves, and with an anterior-posterior polarity (e.g., this includes worms, ants, and ranging up to humans) -- first appeared. A team led by Dr. Mary Droser, professor of geology at the University of California, Riverside, studied "trace" fossils, e.g., burrows, trails and tracks left behind by the earliest bilaterian animals. Results from their study suggest that bilaterian animals did not appear until approximately 555 million years ago.
(Excerpt) Read more at info.ucr.edu ...
TOPICS: Culture/Society; News/Current Events
KEYWORDS: cambrian; crevolist; evolution
The latest news and views from the Cambrian on the origins of left and right.
1
posted on
09/30/2002 7:03:42 AM PDT
by
forsnax5
To: VadeRetro; jennyp; Junior; PatrickHenry; general_re; *crevo_list
Cambrian ping!
2
posted on
09/30/2002 7:09:29 AM PDT
by
forsnax5
To: forsnax5
Not surprisingly, the right side evolved first, paving the way for the evolution of the parasitic left...
To: general_re
Not surprisingly, the right side evolved first, paving the way for the evolution of the parasitic left... Yes, eventually followed by the all-left sided creature, exemplified by Tom Daschel, Hillary, Teddy, etc.
To: PatrickHenry
Fortunately, as having two lefts is an example of devolution, we can expect to see such creatures return to their roots in the primordial slime before too long, much like Teddy oozes now...
To: general_re
Bryozoans, more or less ?
To: Eric in the Ozarks
To: general_re
Nah. That's a pic of what's growing inside Hillary's pantsuit.
To: PatrickHenry
My mistake - I should have known it was fermenting in there, and doing the talking for her...
To: general_re
I should have known it was fermenting in there, and doing the talking for her... And waiting for you ...
To: PatrickHenry
Nothing I can't handle...
To: general_re
Nothing can escape the incredible pantsuit mold!
To: forsnax5
Interesting development...
To: balrog666
Placemarker
15
posted on
10/02/2002 2:47:09 PM PDT
by
Junior
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