Modifiers matching equid:

• extinct,
• wild,
• large,

Simple categories matching extinct:

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