Why are crocodiles much more widespread than alligators?

47 views
0

Is there anything specific that makes crocodiles more widespread?

In: 11

Crocodiles have special adaptations that allow them to tolerate saltwater whereas alligators are strictly limited to freshwater areas. Since freshwater areas are generally isolated and separated by saltwater areas, this confines alligators but not crocodiles.

Well, “in a while” is a shorter time, or at least more specific than just “later”. So when they say “see you later alligator” it’s less likely to happen than the other, “in a while crocodile”.

It’s basically just geography. Figure that two species of non-avian archosaurs made it through the K-T extinction:

1. The ancestor of crocodiles and gavials lived somewhere in Africa and was adapted to be able to survive immersion in saltwater.
2. The ancestor of alligators and caiman lived somewhere in North America and was adapted to be able to survive brief periods of cold weather.

(1) is simply a better starting position for repopulating an empty planet than (2) is:

1. The crocodiles easily spread across Africa, South Asia, Indonesia, and Australia. They also somehow managed to swim across the Atlantic Ocean into the Caribbean.
2. The alligatorids spread with great difficulty (with each passage from one river to another, and each adaptation to a new latitude, being a new challenge) into South America. They also somehow managed to walk across the Bering Land Bridge into China.

And that’s where we find them today.