Data from: Trophic specialisation drives morphological evolution in sea snakes

Viviparous sea snakes are the most rapidly speciating reptiles known, yet
the ecological factors underlying this radiation are poorly understood.
Here, we reconstructed dated trees for 75% of sea snake species and
quantified body shape (forebody relative to hindbody girth), maximum body
length and trophic diversity to examine how dietary specialisation has
influenced morphological diversification in this rapid radiation. We show
that sea snake body shape and size are strongly correlated with the
proportion of burrowing prey in the diet. Specialist predators of
burrowing eels have convergently evolved a ‘microcephalic’ morphotype with
dramatically reduced forebody relative to hindbody girth and intermediate
body length. By comparison, snakes that predominantly feed on gobies are
generally short-bodied and small headed, but there is no evidence of
convergent evolution. The eel specialists also exhibit faster rates of
size and shape evolution compared to all other sea snakes, including those
that feed on burrowing gobies. Our results suggest that trophic
specialisation to particular burrowing prey (eels) has invoked strong
selective pressures that manifest as predictable and rapid morphological
changes. Further studies are needed to examine the genetic and
developmental mechanisms underlying these dramatic morphological changes
and assess their role in sea snake speciation.