Where did the captorhinids go?

Captorhinids were a group of early reptiles estimated to have lived approximately 318-251 million years ago and have been found on every continent except Australia and Antarctica.

800px-Captorhinus_aguti_p

Captorhinus aguti

Though these may look like a typical lizard, they’re actually quite different from any lizard alive today. A major feature of distinction is their skulls. If you look closely at the skull of the captorhinid above, you’ll notice holes for the eyes, but the rest of the skull is solid bone. Contrast that with this modern reptile below called a tuatara:

3063_1large

Notice how there are multiple holes in the side of the skull (two on each side)? This sort of skull is characteristic of modern lizards and is called a diapsid (“two arches”) skull. The captorhinid skull has no holes and is called anapsid (“no arches”). Anapsid skulls are also found in turtles, but turtles are clearly distinct from captorhinids (e.g., shell). In other words, captorhinids are nothing like any species of reptile alive today.

The last geological layer that we last find captorhinids in is called the Permian, which dates to approximately 251 million years ago. This is associated with a mass extinction called the End Permian or Permo-Triassic extinction during which scientists estimate ~96% of all marine species and ~70% terrestrial vertebrates went extinct. Many factors seem to have contributed to this massive die-off including volcanism, methane released from the sea floor, changes in ocean circulation, plate tectonic action, etc. So it appears likely that captorhinids were part of this major extinction, and lost ground to their reptilian relatives.

captorhinidae_by_karkemish00-d544llu

Questions for Creationists

Where did the captorhinids go? Many of these were small, as you can see in the image above, so shouldn’t Noah have been able to fit some onto his ark? If fossils have been found in North and South America, Europe, Africa and Asia, shouldn’t we have found some living today? Or shouldn’t we have evidence of recently deceased individuals?

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4 thoughts on “Where did the captorhinids go?

  1. Pingback: Where did the sea scorpions go? | Evolution For Skeptics

  2. Pingback: Where did the glossopterids go? | Evolution For Skeptics

  3. Pingback: Where did the hyoliths go? – Evolution For Skeptics

  4. Pingback: Where did the gorgonopsians go? – Evolution For Skeptics

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