The Natural History Museum in London has discovered a previously unknown species of coelacanth from fossil remains that date back about 150 years (Macropoma gombessae). The new coelacanth is important because it helps to fill in a huge evolutionary gap of about 50 million years for coelacanths, one of the world’s most recognised ‘living fossils.’ According to the study published by the University of Portsmouth, the fossil was reevaluated by Former University of Portsmouth palaeontology student Jack L. Norton while examining historical collections that he had already been studying for several years. To explore the internal anatomy of this ancient coelacanth fossil without destroying it, researchers from the University of Portsmouth and the Natural History Museum used advanced X-ray computed tomography (XCT) technology to examine the coelacanth fossil’s internal structures in a way that had never been done before. This finding emphasises the vast amount of scientific potential that exists in museum collections worldwide, and provides further evidence of how modern technological innovations can change how we view ancient groups, and show us the complexities of evolutionary processes that have gone unnoticed under our noses for well over the past century.
Discovery of a new coelacanth species from a 150-year-old fossil
As noted by the University of Portsmouth, a specimen named Macropoma gombessae was discovered in the Gault Formation of southern England, dating back to the Lower Cretaceous. This fossil has spent more than 150 years sitting in plain sight in a museum’s collection until it was recently discovered to be a missing link in the family Latimeriidae (i.e. modern-day coelacanths). Gombessa, the Comorian name for the modern coelacanth as used by local fishermen, is where the name is derived from.
Revolutionising discovery with X-ray computed tomography
The specimen was identified using a technique called X-ray computed tomography (XCT), which allows scientists to examine the specimen without damaging it, creating a 3-dimensional image of the specimen and viewing the specimen’s internal features in high definition. The fossil was then directly compared to similar specimens in different genera and found to possess enough distinct anatomical features to classify it as a new species. This also provided a sampling of the evolutionary history of coelacanths.
Revealing internal anatomy with advanced imaging
Researchers utilized X-ray computed tomography (XCT) to re-analyse the fossil (non-destruction method) via three-dimensional visualisation of the material and the interior structures of the specimen; they could thus perform comparative analysis on this specimen with known lineages to verify any unique anatomical feature of this specimen in relation to other fossils; these results indicated that this fossil represented a new coelacanth species and assisted in understanding its evolutionary history.
