Bullfrogs

The bullfrog tadpoles in the holding pond on my street are huge, bigger than my big toe. They have yellow bellies and swim rapidly away when Lily and I approach the pond. I just looked up bullfrogs on Wikipedia and found all kinds of cool words. I'd be a biologist just for the words.

American Bullfrog Rana catesbeiana,
Bullfrogs grow on average to be about 3 and a half to 6 inches (9-15 cm) long in bodylength (although there are records of some as big as 8 inches), legs add another 7-10 inches (17 - 25 cm) to length. Adult bullfrog skeleton is representative of tetrapod vertebrates, comprising an axial skeleton (skull and vertebrae) and an appendicular skeleton (pectoral girdle and forelimbs, pelvic girdle and hindlimbs). Ranids, however, lack ribs. The pronounced pair of dorsal humps in the back of ranid frogs are the ends of the pelvic ilia, homologues of the human hips.

The bullfrog skull is highly fenestrated. The orbits open ventrally through the roof of the mouth to accommodate eye retraction during locomotion and swallowing. The skull bears a continuous row of tiny teeth on the maxilla and premaxilla and a pair of small vomerine teeth on the palate. The mandible is toothless.

The bullfrog nervous system consists of a brain, spinal cord, and peripheral nerves including cranial nerves, spinal nerves, and sympathetic nerves serving organs such as the heart, gastrointestinal tract, kidneys, gonads.

Females have an eardrum (tympanum) the same size as their eye. Males' eardrums are larger.