Thick layers of keratin reduce water loss. Animal is less dependent on moist environment. Provides protection from abrasion, as reptile moves over land. Amniotic egg. During the Carboniferous era, ...

The fossil record of amniotic eggs and embryos is paltry, leaving scientists little knowledge about when, how and why they evolved. ... Sander argues that egg-laying actually came first.

The origin of the amniotic egg ... Sep. 28, 2021 — Eye size likely plays a role in the contest between avian brood parasites -- birds that lay their eggs in the nests of other species ...

The amniotic egg consists of a suite of fetal membranes, including the amnion, chorion and allantois, as well as an external shell that can be either strongly mineralized (as in rigid-shelled eggs ...

A newly created cell model of the amniotic sac could reveal new insights into early pregnancy, as well as generate helpful ...

Hummingbirds lay eggs shaped like Tic Tac mints — “perfect little ellipses,” per ... returning to water to procreate. But amniotic eggs, embryos tucked into fluid-filled shells, proved ...

However, a fresh study of 51 fossil species and 29 living species which could be categorised as oviparous (laying hard or soft-shelled eggs) ... But the amniotic egg was the key.

However, there are some oddballs: Some mammals, such as the platypus, lay eggs, while some reptiles ... These new findings push back the known records of live birth and amniotic embryos by 60 ...

The earliest amniotic eggs contained large amounts of yolk, says James R. Stewart, a reproductive physiologist at East Tennessee State University. “You still see that in birds, crocodilians, and ...

Despite evidence that the earliest examples of creatures such as mammals and reptiles gave birth to live young, they actually may have laid eggs, a scientist argues. IE 11 is not supported.