The Name That Wasn’t

In the annals of taxonomy, few names receive the attention, focus, or hilarity that “Scrotum humanum” has.

The first thing to note about it is the name: scrotum humanum translates from Latin as “human scrotum.” Bet you didn’t see that one coming. This recalled to Richard Brookes the “vague” appearance of a large man’s petrified ball-sack, and the note he placed on a reproduction of Robert Plot’s original figure was simple, effective, and now immortal.

The name was considered attached to a bone from the beds near Chipping Norton in Oxfordshire that have also produced several other Middle Jurassic dinosaur taxa, including Megalosaurus bucklandii (Mantell, 1827). But none of this was known at the time that a small portion of the femur of a large reptile was sent to Robert Plot, who then proceeded to describe the first fossil reptile from England. Subsequently, happening upon the note left in Plot’s Natural History of Oxford-shire, Richard Brookes would label the illustration in key to his larger work in the laboriously named Natural History of Waters, Earths, Stones, Fossils, and Minerals With their Virtues, Properties and Medicinal Uses. Therein, the phrase “Scrotum Humanum” appears, and history is forever altered.

Distal femur in posterior view of a saurischian reptile, and the cover of Plot's Natural Hisotry of Oxford-shire wherein the bone on the left was labeled "Scrotum Humanum."

Or it would have been if anyone else cared for it.

Bev Halstead made short work of re-rediscovering this unusual note, and declared that the material may have threatened the validity of established taxa, if it were found to belong to one of them. Thinking names like Cetiosaurus or Megalosaurus were in threat of becoming “Scrotum,” Halstead (1970) argued that the name used was a valid Linnaean bionomial, as a genus-species couplet “Scrotum humanum,” but that its lack of use and intermittent appearance in listings as a likely synonym rendered it a nomen oblitum. When the name was removed from the list of the ICZN’s nomina oblita, an attempted appeal was rendered unnecessary by the recognition that the name was never used in a form intended for taxonomy, as it was a Latin label as appeared elsewhere in Brookes’ work (Halstead & Sarjeant, 1993). Thus, the name “Scrotum Humanum” simply became scrotum humanum, a term, and thus fall out of taxonomy.

Unfortunately, this has not stopped it being cited and used in taxonomic listings as a junior synonym of Megalosaurus bucklandii, although the most recent treatment of the Stonesfield and New Park Quarry material from Gloustershire and Oxfordshire (Benson, 2010) does not cite, or even list, the material. It has thus slipped back into obscurity, almost certainly where it belongs barring a need for a joke.

Benson, R. B. J. 2010. A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods. Zoological Journal of the Linnaean Society 158(4):882-935.
Brookes, R. 1763. The Natural History of Waters, Earths, Stones, Fossils, and Minerals With their Virtues, Properties and Medicinal Uses: To which is added, The method in which LINNAEUS has treated these subjects. Vol. V. Newberry (London).
Halstead, L. B. 1970. Scrotum humanum Brookes, 1763 — the first named dinosaur. Journal of Insignificant Research 5(7):14-15.
Halstead, L. B. & Sarjeant, W. A. S. 1993. Scrotum humanum Brookes — The earliest name for a dinosaur? Modern Geology 18:221-224.
Mantell, G. 1827. Illustrations of the geology of Sussex: a general view of the geological relations of the southeastern part of England, with figures and descriptions of the fossils of Tilgate Forest. (Privately published.)
Plot, R. 1677. The Natural History of Oxford-shire, Being an Essay Toward the Natural History of England. (Oxford).