Sessile Mobility

Sucker-footed bat Source: Guardian Live

Sucker-footed bat
Source: Guardian Live

A study on sucker-footed bats (Myzopoda aurita), published in PLOS One, discusses bat fossils found in Egypt’s Western Desert. This might be less worthy of examination if the fossils weren’t almost identical with existing bats now found only on Madagascar. These bats have sessile, or immovable, pads for feet.

Based on their research, study authors were able to reach a couple of interesting conclusions based on these tiny, ancient bat jaws. For one thing, the fossils provide evidence of a bat lineage that is 37 million years older than previously assumed.

Animated illustration of the break-up of Gondwana into present-day continents. Based on the bat fossils found, it's assumed that bats which originated in Africa, migrated into Australia, and were able to cross Antarctica into what is now South America. Source: Churchilll Science

Animated illustration of the break-up of Gondwana into present-day continents. Based on the bat fossils found, it’s assumed that bats which originated in Africa, migrated into Australia, and were able to cross Antarctica into what is now South America.
Source: Churchilll Science

This finding, in turn, provides evidence of when and how continental drift took place – the bats were apparently able to cross between continents while the land masses were either still attached, or while there were still dry land bridges between them. Continental drift contributed to the diversification of the bat family by separating and isolating their various groups. The sucker-footed bat was likely once more widespread.

Photo: Merlin D. Tuttle / Bat Conservation International

Photo: Merlin D. Tuttle / Bat Conservation International

In any case, the modern bat with the feet of a tree frog and that lives on Madagascar is the real reason I wanted to post this today. Because they are the only kind of bat that doesn’t hang upside, they live in palm fronds, they have ears that look like their palm frond homes, and they hang on to the slippery surface of leaves using feet that look like something from a child’s drawing.

Group of bats inside a palm leaf. Source: Arkive

Group of bats inside a palm leaf.
Source: Arkive