[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
RE: Paleontology and Dinosaurology 101: What layperson MUST to know about?
- To: <email@example.com>, <firstname.lastname@example.org>
- Subject: RE: Paleontology and Dinosaurology 101: What layperson MUST to know about?
- From: "Thomas R. Holtz, Jr." <email@example.com>
- Date: Mon, 7 Feb 2011 08:23:24 -0500
- Authentication-results: msg-ironport2.usc.edu; dkim=neutral (message not signed) header.i=none
- In-reply-to: <AANLkTikEHuEM6wbX+TUDfi+gpAvJnRdRXVGMY=ooaWfz@mail.gmail.com>
- Reply-to: <firstname.lastname@example.org>
- Sender: owner-DINOSAUR@usc.edu
> -----Original Message-----
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu]
> On Behalf Of Renato Santos
> Sent: Monday, February 07, 2011 7:18 AM
> To: email@example.com
> Subject: Re: Paleontology and Dinosaurology 101: What
> layperson MUST to know about?
> Dr Holtz,
> Great post but if I may be so bold as to point out the
> imprecision in this:
> > * While most of the coal swamp plants reproduced by means
> of spores,
> > one branch evolved a method of reproduction using a seed.
> Spermatophytes still reproduce by means of spores, pollen and
> macrospores: a seed has a greater analogy to an amniote egg.
True enough: this was obviously simplified.
> > * Early terrestrial vertebrates were often competent at
> moving around
> > on land as adults, but typically had to go back to the
> water in order
> > to reproduce. In the coal swamps one branch of these
> animals evolved a
> > specialized egg that allowed them to reproduce on land, and
> thus avoid
> > the tadpole stage.
> I was under the impression that the tadpole stage was a
> specialization of Anura+Caudata...
Juvenile semouryiamorphs, temnospondyls, and others have external gills and
were fully aquatic: "tadpoles" in the broad sense.
Thomas R. Holtz, Jr.
Email: firstname.lastname@example.org Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Faculty Director, Science & Global Change Program, College Park Scholars
Mailing Address: Thomas R. Holtz, Jr.
Department of Geology
Building 237, Room 1117
University of Maryland
College Park, MD 20742 USA