The fossil fish ‘Dunkleosteus terrelli’, a predatory fish that terrorized the seas some 370 million years ago, and reputed for their alleged enormous size, were much smaller than originally presumed, new study in Multidisciplinary Digital Publishing Institute reveals.
Previous estimate of length for this fish ranged from 5 to 10 m, but they were not based on rigorous statistical analysis, of their head and chest, which are their only part preserved in the fossil record. The new study generated new estimates for D. terrelli based on a new metric, the “orbit-opercular length,” which reduced the estimated length of this fossil fish to almost half than originally assumed, with an average size of 3.4 m for adults, and a maximum length of 4.1 m.
The new method used a large dataset of 3169 observations for 972 species of ancient and extant fishes, with J.E. Randall’s “Collection of 10,000 Large-Format Photos (Slides) of Dead Fishes” included and accessed from FishBase.
“An interesting fish tale in which FishBase helped in reducing a Devonian monster fish to size,” Daniel Pauly, not involved in the study, remarked. “Now, its size has ceased to be an anomaly that the Gill Oxygen Limitation Theory would have problems accommodating,” says Pauly, the creator of this theory, and co-creator of FishBase.
The paper “A Devonian Fish Tale: A New Method of Body Length Estimation Suggests Much Smaller Sizes for Dunkleosteus terrelli (Placodermi: Arthrodira)” was published in Multidisciplinary Digital Publishing Institute (MDPI), doi: doi.org/10.3390/d15030318.