Assertion: alligator gar | /r/HasProperty | living fossils
Facets:
value: despite being a highly evolved species
type: OTHER
value: often
type: TEMPORAL
Source sentences:
text: Despite being a highly evolved species, alligator gar are often referred to as "primitive fishes" or "living fossils" because they have retained a few morphological characteristics of their earliest ancestors with seemingly few to no apparent changes, such as a spiral valve intestine, which is also common to the digestive system of sharks, an abbreviate heterocercal tail, and a swim bladder lung for breathing in both air and water.