i.e. is there a word for something like an entry in a natural history dictionary? I poked around trying unsuccessfully to find one, and I'll probably just use "description", but I still have a nagging feeling that there's a word for this, something similar to using "morphology" or "pathology" as countable nouns.
is the term used by the University of Miami to include the morphology, behavior etc. of an animal.
Alternatively, lots of academic papers seem to use
You can find here an example used by the California Academy of Science for some type of shrew.
What's interesting is that the term encompasses everything related to biology: Phylogeny, taxonomy, morphology... See all the sub-sections they use below:
And last, if you focus only on physical characteristics you could use