Rays & Chimaeras
Flattened batoids, electric rays, and ghost chimaeras — the cartilaginous fish relatives of sharks that evolved extraordinary body plans over 200 million years.
Overview
Rays (batoids) and chimaeras (holocephalans) are the flattened and deep-water branches of the cartilaginous fish family tree. Skates, stingrays, sawfish and mantas patrol the seafloor and open water, while chimaeras — 'ghost sharks' — have ground their prey with tooth plates since the Mesozoic.
Quick Facts
Key Characteristics
- •Rays: flattened disc with enlarged pectoral fins; mouth and gills on the underside
- •Venomous tail spines in stingrays; sawfish rostra studded with electroreceptive teeth
- •Chimaeras: tooth plates instead of replaceable teeth, large pectoral fins, whip-like tail
- •Cartilaginous skeleton with calcified surface prisms
Fossil Record
Isolated teeth, denticles and chimaera tooth plates are common in Jurassic–Cretaceous marine beds; complete rays and chimaeras are known from Solnhofen, Lebanon lithographic limestones and Monte Bolca.
Global Distribution
Global in marine rocks since the Mesozoic; tooth plates especially abundant in European Jurassic and Cretaceous deposits.
Evolutionary & Scientific Importance
Batoids and holocephalans document a second major radiation of cartilaginous fishes and the evolution of flattened, durophagous body plans; their myliobatid crushing teeth reveal the history of shell-crushing predation on bivalves.