Echelus (Rhynchorhinus) branchialis

Rhynchorhinus branchialis is a confusing species of extinct Eel due to the fact that the holotype and paratype specimens are very poorly preserved and very worn. A recent paper, examining a perfectly preserved specimen from Aveley, places this specimen as Rhynchorhinus branchialis although this specimen also shares a lot of similarities to Rhynchorhinus major as you’ll see from the photos below. It is my belief that there are at least 4 different morphologies of Eel skulls that I’ve observed within the London clay so I’ll be looking into this topic a little further shortly.

Distinguishing Characteristics:

Centrally raised ridge running across the rear of the top of the skull (1)
Elongated, pointed-shape to the skull (2)
Multiple rows of small, sharp, retrorse teeth (3)

Primary Example: NHMUK PV P 65205

3D Scan - NHMUK PV P 65205

3D scans undertaken by Tom Sermon with permission.

Primary Example: Holotype NHMUK PV P 633

Additional Example: Paratype NHMUK PV P 163

References

Young, S. (2013) New information on the cranial anatomy of the eel genus Echelus Rafinesque, 1810 (Ophichthidae: Anguilliformes) from the Early Eocene
Casier, E. (1966) Fauna ichthyologique du London Clay. British Museum Natural History London, 1966, 1-496
Monsch, K (2005) Revision of the scombroid fishes from the Cenozoic of England
Rayner, Mitchell, Clouter (2009) London Clay Fossils of Kent and Essex