A fossil expert from Northumberland is exploring the world of 20 million years ago as part of his work in the United States.
But he now works at the University of Illinois, where he is searching through a massive collection of 20-million-year-old amber found in the Dominican Republic more than 50 years ago.
The work is yielding fresh insights into ancient tropical insects and the world they inhabited.
Dr Heads graduated in the UK in palaeobiology and evolution and took a PhD in palaeontology - the study of fossils and ancient life.
He said: “When I was about five or six years old, I was walking along the coast at Seaton Sluice in Northumberland with my dad when I came across a fossil. He explained to me what it was and I was immediately hooked.”
Dr Heads took up his job in the United States in 2009.
The most striking discovery so far in the amber project is that of a pygmy locust, a tiny grasshopper the size of a rose thorn that lived 18 to 20 million years ago and fed on moss, algae and fungi. The specimen is remarkable because it represents an intermediate stage of evolution in the development of locusts.
The most ancient representatives of this group had wings, while modern counterparts do not.
The newly discovered locust has what appear to be vestigial wings — remnant structures that had already lost their primary function.
“Grasshoppers are very rare in amber and this specimen is extraordinarily well-preserved,” said Dr Heads, who works at the Illinois Natural History Survey (INHS), a division of the Prairie Research Institute at the University of Illinois.
Dr Heads, laboratory technician Jared Thomas and study co-author Yinan Wang found the new specimen a few months after the start of their project to screen more than 160 pounds of Dominican amber collected in the late 1950s by former INHS entomologist Milton Sanderson. Sanderson described several specimens from the collection in a paper in Science in 1960, a report that inspired a generation of scientists to seek out and study Dominican amber, said Dr Heads .
The bulk of the Sanderson amber collection remained in storage, however, until Dr Heads uncovered it in 2010.
He has named the new pygmy locust Electrotettix attenboroughi, the genus name a combination of electrum (Latin from Greek, meaning “amber”) and tettix (Greek, meaning “grasshopper”).
The species is named for naturalist Sir David Attenborough, whose actor brother who appeared in the movie Jurassic Park.
“Sir David has a personal interest in amber, and also he was one of my childhood heroes and still is one of my heroes and so I decided to name the species in his honour, with his permission of course,” said Dr Heads.
The process of screening the amber is slow and painstaking. Much of the amber is clouded with oxidation, and the researchers must carefully cut and polish “windows” in it to see what’s inside. In addition to the pygmy locust, Dr Heads and his colleagues have found mating flies, stingless bees, gall midges, Azteca ants, wasps, bark beetles, mites, spiders, plant parts and even a mammal hair. The pygmy locust was found in a fragment that also contained wasps, ants, midges, plant remnants and fungi.
Such associations are rich in information, said Dr Heads, offering clues about the creatures’ needs and the nature of their habitat.
“Fossil insects are a tremendous resource for understanding the ancient world, ancient ecosystems and the ancient climate - better even, perhaps, than dinosaur bones,” said Dr Heads.