[Grammar] be verb + number

[langue]

I found the sentence in the BBC article:
A study in recent months suggested that the giraffe was actually four different species.

Is this grammatically correct? Because I never heard <Subject> <be verb> <number> order.

I would say, there were four species of giraffe.

Thank you

 

[PaulMatthews]

A study in recent months suggested that the giraffe was actually four different species.


It's fine.

The order of the underlined expression is Subj - Verb - Complement, where the Complement is the noun phrase "four different species".