Short answers, pulled from the story.
The oldest confirmed ray fossil Antiquaobatis emerged from the Pliensbachian stage of the Jurassic period in Germany. This fossil marks the beginning of a lineage that would come to dominate the ocean floor.
Most batomorph species have five gill slits located on the ventral surface beneath the pectoral fins. The Hexatrygonidae family stands out with six gill slits instead of the typical five.
A 2021 study published in Nature revealed that the number of oceanic sharks and rays has declined globally by 71% over the preceding 50 years. Overfishing has increased the global extinction risk of these species to the point where three-quarters are now threatened with extinction.
Some batomorph species dwell in deep waters to at least 3,000 meters. The majority of batomorphs have a cosmopolitan distribution, preferring tropical and subtropical marine environments.
There are well over 600 species of batomorphs distributed across 26 families. This makes rays the most speciose group of cartilaginous fishes.