Skinks shed tails and hide necks across fifteen hundred species
Scincidae packs more than 1,500 described species into about a hundred genera, making skinks one of lizard life's most diverse families. Most look short-necked with modest legs, yet many can drop a tapering tail and regrow it imperfectly within roughly three to four months.
English borrowed skink around 1580–1590 from Greek skinkos and Latin scincus, old names for particular lizards. Compared with lacertid "true lizards," typical skinks blur the neck and shrink the limbs, though showy species such as the red-eyed crocodile skink break that silhouette. Bony scales armour the skull in matching, overlapping plates. Some lineages, including Neoseps, keep fewer than five toes and wriggle like snakes, while Typhlosaurus has lost its legs entirely.
Autotomy is a signature defence: a predator that seizes the tail may be left holding a twitching decoy while the lizard escapes, and the replacement grows back, imperfectly, within about three to four months. Sizes run from Scincella lateralis at roughly 7.5–14.5 cm, over half of it tail, through the usual snout-vent length near 12 cm, up to the Solomon Islands skink, which may reach some 35 cm before the tail even starts. Prasinohaema species go further into the strange: a buildup of biliverdin turns their blood green.
Reproduction is where the family becomes a textbook case. Most skinks lay eggs, yet around 45% of species give birth to live young in some fashion. In Tiliqua and Corucia the embryos feed through a placenta much like a mammal's, and Trachylepis ivensi has a purely reptilian placenta comparable to the eutherian kind. These arrangements arose independently many times, so they resemble mammalian placentas by convergence rather than shared ancestry.
The lineage is old. Electroscincus zedi, preserved in Burmese amber about 100 million years old, already sits inside the crown group, so the living subfamilies had begun splitting by then. Skinks make up about 15% of reptiles, carry only 11 to 16 chromosome pairs, and share an XY sex system older than 80 million years. The first skink reference genome, from the Christmas Island blue-tailed skink, was sequenced in 2022.
Source: Skink
