Leptolepis is usually classed as an
early teleost. In particular,this
herring-like swimmer possessed a
fully ossified (bony) vertebral
column, or backbone. In addition,
its scales lacked a heavy enamel
coating and were much thinner
and lighter than in 'more primitive
fish; as well as being more flexible
and more cycloidal, or rounded,
in shape. Leptolepis remains are
most abundant in jurassic rocks,
where entire fossilized schools of
hundreds of individuals can be found on
single slabs. Other, more fragmentary remains
indicate that the genus persisted throughout
almost the whole Mesozoic Era. These
relatively small, warm-sea fish fed on the
small planktonic organisms.