#ranidae

[herpsandbirds]

Crayfish Frog (Lithobates areolatus), family Ranidae, IN, USA

These frogs live underground, often in crayfish burrows.

photos via: Indiana Department of Natural Resources

[markscherz]

Look at these generic-ass frogs.

This is just a Frog™, right?

Wrong. These four frogs belong to four different families (respectively, Dicroglossidae: Limnonectes paramacrodon, Ranidae: Rana temporaria, Mantellidae: Aglyptodactylus madagascariensis, and Pyxicephalidae: Amietia tenuoplicata) from across the world (respectively, I took these photos in Borneo, Denmark, Madagascar, and Tanzania).

These represent just some of the huge number of genera across more than half a dozen families that have independently produced species that look like this:

In Europe: Ranidae: Rana. In North America: Ranidae: Boreorana/Lithobates. In South America: Leptodactylidae: Leptodactylus. In Africa: Pyxicephalidae: Amietia or Arthroleptidae: Arthroleptis. In Madagascar: Mantellidae: Aglyptodactylus. In mainland Asia: any of a dozen or more genera of the family Ranidae; or Ranixalidae: Indirana. In Australia: Pelodryadidae: Rhyaconastes. and more, besides!

Why? Well… that is kind of a fundamental question in evolutionary biology. Why, with the infinite theoretical possibilities of evolutionary processes, do we see the same kind of anatomies evolving again and again? Does this mean that evolution is in some way predictable?

The answer is complex (there are good books on this topic!), but basically, yes: similar pressures can (but do not always) lead to similar solutions. I think this may apply to frogs to an exceptional degree, in part because their body plans are so simple to start with, that the tools available for tinkering are pretty streamlined and refined. These are just one stark example, but you can do this with whole ecological assemblages of frogs in some cases. Madagascar is especially excellent for this, because the island was only naturally colonised by frogs five times, and yet you have practically every main 'type' of frog there, independently derived from one of these colonising lineages.

Yet, each of these generic brown frogs is also subtly different—and their skeletons reveal pretty fundamental differences unique to their lineages. Not to mention their totally distinct tadpoles!! And that is part of the key, too: although some parts of evolution can be predictable, no organism can separate itself from its own evolutionary past. There is always a degree of contingency involved.

I find these frogs to be a really elegant demonstration of this principle. And also, a nice demonstration of why it is fucking impossible to ID frog pictures you guys send me without a more or less precise location.

Thanks for coming to my TED talk.

[snototter]

Common frog (Rana temporaria) tadpoles mass together in England

by Will Atkins

[miyrumiyru]

Cute green frog and brown-red frog

[uncharismatic-fauna]

Uncharismatic Fact of the Day

No one likes basking by the pool more than the pool frog! Pool frogs spend most of their time near slow-moving or still bodies of water including marshes, bogs, and ponds, where they bask in the sun on even the hottest days. They like the sunshine so much that they even breed late, typically in late May or June.

(Image: A pool frog (Pelophylax lessonae) by Piet Spaans)

[every-day-creechur]

California red-legged frog Rana draytonii

From the foothills of the Sierra Nevada mountains in California and northern Baja California. They are federally threatened and named the "state amphibian" of California in 2015.

[have-you-seen-this-animal]

Wood frog! The only frog that lives in the arctic circle (I think?) Never seen em in person but I like em so :D

Have you seen the wood frog (Lithobates sylvaticus)?

I have now

Yes, in photos/videos

Yes, irl

I'm not sure

Voting ended onSep 23, 2025

I did check to see if this is the only frog found in the Arctic circle, but it looks like the European common frog (Rana temporaria) is also found there. There may be other species found in the Arctic circle as well, I only did a small bit of searching. Wood frogs do have an incredible tolerance to cold, and partial freezing though, which is amazing! The Japanese tree frog (Dryophytes japonicus) has an even bigger cold tolerance, with a potential to survive temperatures as low as −35 °C (−31 °F) for up to 120 days.

[landmineblogging]