Quadrupedal means walking on four legs. A quadrupedal dinosaur.
Weight is what usually decides it, since the largest animals need four legs to carry themselves. Several dinosaur lines went from two legs to quadrupedal as they grew heavier.
1adjectivequadrupedalWalking on four legs.
“The quadrupedal ones left tracks with a wider gauge.”
quadrupedal is a quality.
From quadruped + -al.
Etymology from Wiktionary, CC BY-SA