Group of animals and horse featuring in my research material (8)

I believe the answer is:

chordata

I'm a little stuck... Click here to teach me more about this clue!

'group of animals' is the definition.
'chordata' can be an answer for 'animals' (I've seen this before). I'm unsure of the 'group of' bit.

'horse featuring in my research material' is the wordplay.
'horse' becomes 'H' (abbreviation as in horse power).
'featuring in' is an insertion indicator.
'my' becomes 'cor' (both are expressions of surprise).
'research material' becomes 'data' (I've seen this in another clue).
'h' placed within 'cor' is 'chor'.
'chor'+'data'='CHORDATA'

'and' is the link.

Can you help me to learn more?

(Another definition for chordata that I've seen is " animals".)

I've seen this clue in The Times.

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