A weird spiny coelacanth from the Late Jurassic of Solnhofen questions the evolutionary pace of the group

We obtained temporary permission to study the only fossil specimen of a very unusual Late Jurassic coelacanth fish from Solnhofen, recently acquired by the Natural History Museum in München. While most coelacanth taxa show a very monotonous morphology, this one differs as it exhibits superficial characteristics similar to pufferfishes (Tetraodontiformes) (balloon-shaped body, elongated spines, possible presence of a large lung), indicating a potential swelling capacity of the body (Fig1A). This hypothesis can only be verified by detailed observations of the anatomical structures - intracranial articulation, histology of the dermal spines and fine anatomy of the scales - in synchrotron light. The anatomy and morphological characterization of this specimen will enrich an ongoing project on the evolutionary characteristics of coelacanths, that is, their monotonous or highly derived anatomy and body plan, and the genetic and developmental causes at the origin of these life traits.