Question

crocodilemus was an ancient animal that lived in the sea about 150,000,000 years ago. here are pictures of a crocodilemus fossil, a living nile crocodile, and a living bottlenose dolphin.

images of crocodilemus, nile crocodile, bottlenose dolphin

which traits can you observe in the fossil of crocodilemus, the living nile crocodile, and the living bottlenose dolphin? complete the table.

trait	crocodilemus	nile crocodile	bottlenose dolphin
bony plates on its back
a long, pointed snout
front and back legs
front flippers

Explanation:

To solve this, we analyze each trait by observing the images:

• A tail fin: Crocodilemus (fossil) – check (from its body shape, likely had a tail fin for sea life); Nile crocodile – no (has a regular tail, not a fin); Bottlenose dolphin – check (has a tail fin).
• Bony plates on its back: Crocodilemus – check (fossil shows bony plates); Nile crocodile – check (crocodiles have bony plates); Bottlenose dolphin – no (no bony plates).
• A long, pointed snout: Crocodilemus – check (fossil has a long snout); Nile crocodile – check (crocodiles have long snouts); Bottlenose dolphin – check (dolphins have long, pointed snouts).
• Front and back legs: Crocodilemus – check (fossil shows leg - like structures); Nile crocodile – check (has legs); Bottlenose dolphin – no (has flippers, not legs).
• Front flippers: Crocodilemus – check (fossil has flipper - like front limbs); Nile crocodile – no (has legs); Bottlenose dolphin – check (has front flippers).

We mark the checkboxes based on these observations.

Answer:

Trait	Crocodilemus	Nile crocodile	Bottlenose dolphin
Bony plates on its back	$\boldsymbol{\checkmark}$	$\boldsymbol{\checkmark}$	$\square$
A long, pointed snout	$\boldsymbol{\checkmark}$	$\boldsymbol{\checkmark}$	$\boldsymbol{\checkmark}$
Front and back legs	$\boldsymbol{\checkmark}$	$\boldsymbol{\checkmark}$	$\square$
Front flippers	$\boldsymbol{\checkmark}$	$\square$	$\boldsymbol{\checkmark}$