Evolved from pioneering bichirs who took to the land for both shelter and food have grown immensely in size. Their flippers greatly adapted to live a mostly terrestrial life. Bones and muscles anchored down onto sturdier shoulder blades. To accommodate this newly terrestrial life style, the necks on these fishes have lengthened and increases in vertebrae number to give them a longer more flexible range with their necks. This flexibility is useful for looking out for prey or for rivals.
While the "sand" in their name implies they're mostly around sandy biomes, this is simple not the actual case. While their ancestors were primarily beach goers, they have migrated inland however into more forested biomes. Being the biggest terrestial predator as off now, they have become the apexes of several ecosystems. Though these sandracos tend to be different than each other, with adaptions unlike the others potentially being the way for differnt unique forms. A few notable examples of these subspecies are Foresters and Mudflatters.
Mudflatters tend to support stronger pectoral fins, with increased muscle anchors and exposed fin tips. These adaptations are useful for digging up large terrestial amphipods and snails. However these exposed claw tips are useful in fighting each other, males would usually rear up and claw each other. The Forestors of the Anubia and Rice forests are similiar to mudflatters, though their back fins are more prehensile and stronger. This is to aid it in it's odd hunting style, sneaking up on trees and lunging out at soarers and bugs. The back fins anchor it in place so it doesn't fall and injure itself.
A unique and interesting creature, one filled with so much potential. Oh the wonderful clades it shall birth.