In an incredible two-for-one fossil find, palaeontologists have discovered a 75-million-year-old dinosaur jawbone with some surprise-laden prehistoric amber on the side. Nestled within the unusually large blob of resin were fragments of trees and the remains of an unlucky aphid.
The find, which is the first of its kind in North America, according to Science, stunned scientists when it was announced in a 2019 paper, not least because of the extremely unlikely chain of events that brought about its preservation.
The jawbone, unearthed in 2010 in Dinosaur Provincial Park in Alberta, Canada, belonged to a duck-billed hadrosaur called Prosaurolophus maximus. Hadrosaurs were incredibly common during the Late Cretaceous in North America; however, very little is known about their habits, which makes this find all the more exciting as it offers a rare glimpse into the dinosaur’s diet and lifestyle.
Equally as enthralling for palaeontologists is the piece of amber found clinging to it. While Cretaceous amber is relatively abundant – and this isn’t the first time we’ve found creepy crawlies embedded in it – it is very rare to come across the gemstone directly associated with dinosaur remains, let alone with a bonus insect fossil to boot.
In fact, something really extraordinary must have taken place for this to come to pass.
“The series of events required for preservation of insect-bearing amber in direct association with dinosaur remains is remarkable,” the researchers behind the discovery wrote in their paper.
Firstly, they believe, the hadrosaur must have died, and its remains undergone decomposition, before being washed into a river. Simultaneously, a blob of resin from either a redwood or an araucarian conifer tree, containing the trapped aphid, fell into the water and was pushed up against the jawbone by the current. Over tens of millions of years, the duo became buried in sediment, during which time the resin hardened into amber and the whole sorry dino-insect-amber situation came about.
If the resin and the jawbone had come into contact at a slightly different stage, the authors add, the amber may even have been able to reveal microscopic details of the hadrosaur itself. But even without this, it can still spill some secrets.
For example, the fossilized remains suggest that some hadrosaurs fed on conifers near coastal plains.
“In addition to providing paleoecological information, future finds of bonebed amber may provide insights that are not available from skeletal remains alone, and they certainly warrant attention during the excavation and preparation processes,” the researchers conclude.
The study is published in Scientific Reports.