Modifiers matching equid:

• wild,
• extinct,
• large,

Simple categories matching extinct:

• mammal,
• animal,
• predator,
• equid,
• human,
• creature,
• vertebrate,
• archosaur,
• organism,
• giant,
• herbivore,
• fauna,
• reptile,
• ratite,
• amniote,
• bird,
• plant,
• relative,
• beast,
• dinosaur,