Some teeth have a more variable internal anatomy than others.
These classes were ultimately created by studying the internal anatomy, as seen in his key:
Their internal anatomy includes a radula and a primitive brain.
On some specimens, details of the internal anatomy can be seen due to the exceptional preservation.
The internal anatomy of this genus is not known.
At the time this, with the rest of the internal anatomy of the brain, was quite new to him.
Little is known of the internal anatomy of the Protoss.
Still, you could never be sure with these primitives he thought, forgetting that Bruce's internal anatomy was the same as his own.
Little is known of the internal anatomy, although the gut apparently ran straight and all the way from the front to the rear.
The internal anatomy, I may remark here, as dissection has since shown, was almost equally simple.