Ancient 'Kite Runner' carried its babies in bubbles: study

 Scientists have discovered a bizarre ancient animal that carried its babies in capsules tied to the parent's body like tiny, swirling kites and named it after the 2003 bestselling novel 'The Kite Runner'.

The minuscule creature, Aquilonifer spinosus, was an arthropod that lived about 430 million years ago, researchers said.

It grew to less than half an inch long, and there is only one known fossil of the animal, found in Herefordshire, England, they said.

Its name comes from "aquila," which means eagle or kite, and "fer," which means carry.
"Modern crustaceans employ a variety of strategies to protect their eggs and embryos from predators - attaching them to the limbs, holding them under the carapace, or enclosing them within a special pouch until they are old enough to be released - but this example is unique," said Derek Briggs from Yale University in the US.

"Nothing is known today that attaches the young by threads to its upper surface," said Briggs.

The Kite Runner fossil shows 10 juveniles, at different stages of development, connected to the adult.

Researchers interpret this to mean that the adult postponed molting until the juveniles were old enough to hatch; otherwise, the juveniles would have been cast aside with the shed exoskeleton.

The adult specimen's head is eyeless and covered by a shield-like structure, researchers said.

It lived on the sea floor during the Silurian period with a variety of other animals including sponges, brachiopods, worms, snails and other mollusks, a sea spider, a horseshoe crab, various shrimp-like creatures, and a sea star, they said.

The juvenile pouches, attached to the adult by slender, flexible threads, look like flattened lemons.

Researchers considered the possibility that the juveniles were parasites feeding off a host, but decided it was unlikely because the attachment position would not be favourable for accessing nutrients.

"We have named it after the novel by Khalid Hosseini due to the fancied resemblance of the juveniles to kites. As the parent moved around, the juveniles would have looked like decorations or kites attached to it," said Briggs.

"It shows that arthropods evolved a variety of brooding strategies beyond those around today - perhaps this strategy was less successful and became extinct," Briggs said.

Researchers were able to describe Aquilonifer spinosus in detail due to a virtual reconstruction. They reconstructed the animal and the attached juveniles by stacking digital images of fossil surfaces showed by grinding away the fossil in tiny increments.
The findings were published in the journal PNAS.