amniote

The origin and early evolutionary history of amniotes.

We applied our methods to DNA sequences from two nuclear (18S and 28S) and three mitochondrial genes (12S, 16S, valine tRNA) taken from representative taxa from a relatively noncontroversial and well-studied four-taxon amniote phylogeny (Sceloporus undulatus, Alligator mississippiensis, Gallus gallus, and Mus musculus: alignments [TABULAR DATA FOR TABLE 1 OMITTED] and GENBANK accession numbers as described in Hedges et al.

By double-clicking on a picture, the student views a pop-up window with a list of traits (eukaryotic cells, amniote egg, jaws, etc.

Unlike other mammals, monotremes, like the platypus, never evolved to give live birth, but instead lay eggs like their amniote ancestors.

Knowing how a basic amniote embryo ends up developing into something so radically different could shed light on turtle history, says paleontologist Michael Lee of the South Australian Museum at the University of Adelaide.

The brain-body ratios of amphibians are even less than those in reptiles (Jerison, 2001), and as discussed above, their fore-brains lack the thalamopallial circuitry of amniote brains.

A time of forests, swamps, seed ferns, mosses, lycopods and the origin of the amniote egg.

The water-tight amniote egg of reptiles was somewhat larger and still had to pass through this circular ring of bone.

Common Leaf-tailed Geckos (Uroplatus fimbriatus) have the distinction of having more teeth than any other amniote (terrestrial vertebrate).

Amniote origins: completing the transition to land.

For the analysis, Rieppel and deBraga compiled an extensive data matrix for amniota (reptiles, birds, and mammals) that included 33 amniote groups and 168 characteristics of their bones -- an important physical characteristic in defining clades.

The researchers' map also provides a significant step towards the elucidation of the crocodilian genome, forming a scaffold for genome sequence assembly, and will be of intrinsic value to comparative mapping efforts aimed at understanding the molecular evolution of reptilian, as well as other amniote genomes.

Casineria pulls back the origin of amniote lineages much farther than was previously realized.

caprodes, transitions (TR) outweighed transversions (TV), a pattern similar to amniote CR sequence (11 TR :3 TV versus 10 TR: 1 TV or greater for amniote CR [Brown et al.

In most amniote tetrapods, the lateral walls of the nasal cavity exhibit one or more conchal projections, which provide additional surface area for nasal epithelia (Matthes 1934; Parsons 1971; Romer and Parsons 1986).