Chronological appearance of cardiac structures.

<p>The corn snake and the sailfin lizard have been aligned because both have similar incubation times after egg laying. In comparing squamate heart development to other vertebrates, the developing hearts of the corn snake of 2 to 14 days and the anoles of stages 5 to 9 correspond in many regards to, we suggest, the hearts of chicken development of Hamburger-Hamilton stages 18–28 and of human development of Carnegie stages 14 to 18. Later stages differ substantially.