Some hatching mechanisms unchanged from 130 mya

Amber is as close as paleontology comes to video. It can almost capture actions. From ScienceDaily:

Trapped together inside 130 million-year-old Lebanese amber, or fossilised resin, researchers found several green lacewing newborn larvae, the split egg shells from where they hatched, and the minute structures the hatchlings used to crack the egg, known as egg bursters. The discovery is remarkable because no definitive evidence of these specialised structures had been reported from the fossil record of egg-laying animals, until now.

The fossil newborns have been described as the new species Tragichrysa ovoruptora, meaning ‘egg breaking’ and ‘tragic green lacewing’, after the fact that multiple specimens were ensnared and entombed in the resin simultaneously.

“Egg-laying animals such as many arthropods and vertebrates use egg bursters to break the egg surface during hatching; a famous example is the ‘egg tooth’ on the beak of newborn chicks,” explains Dr Ricardo Pérez-de la Fuente, a researcher at Oxford University Museum of Natural History and lead author of the work. “Egg bursters are diverse in shape and location. Modern green lacewing hatchlings split the egg with a ‘mask’ bearing a jagged blade. Once used, this ‘mask’ is shed and left attached to the empty egg shell, which is exactly what we found in the amber together with the newborns.”

Green lacewing larvae are small hunters which often carry debris as camouflage, and use sickle-shaped jaws to pierce and suck the fluids of their prey. Although the larvae trapped in amber differ significantly from modern-day relatives, in that they possess long tubes instead of clubs or bumps for holding debris, the studied egg shells and egg bursters are remarkably similar to those of today’s green lacewings. Altogether, they provide the full picture of how these fossil insects hatched like their extant counterparts, about 130 million years ago during the Early Cretaceous. Paper. (open access) – Ricardo Pérez-de la Fuente, Michael S. Engel, Dany Azar, Enrique Peñalver. The hatching mechanism of 130-million-year-old insects: an association of neonates, egg shells and egg bursters in Lebanese amber. Palaeontology, 2018; DOI: 10.1111/pala.12414 More.

One wonders whether the larval tubes (as opposed to clubs or bumps) relates to different plant species providing the camouflage, hence different portage methods used. Otherwise, this is a lovely example of stasis (for very long periods of time, evolution doesn’t seem to happen), trapped in amber.

See also: Millipedes Found In 100 Mya Amber Comprise 13 Of 16 Known Groups

and

Stasis: Life goes on but evolution does not happen

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