Lizard with a Double-Ended Tail—Is That All?
Authors: Rutherford Mike 
Published: September 2024

Specimen GLAHM:120240 (Fig. 1) has been on display in The Hunterian Anatomy Museum at the University of Glasgow for more than a century labelled as “Lizard with Double-ended Tail.” An interesting enough reason for display and being under the spotlight perhaps? Maybe not: examples of lizards being found with two, or even more, tips to their tails are not that uncommon and is possible due to their caudal autotomy behaviour, where a lizard can shed its tail when attacked by a predator to provide a distraction and a possible means of escape. However, if a tail is only partially shed during an incident then sometimes another tip may start to grow at the break point, eventually resulting in two tips to the tail. There are many examples of this phenomenon viewable from a quick online search, and specimens showing this can often be seen in museums, collected and displayed as curiosities.

Is having a lizard on display in an anatomy museum reason enough for being in the spotlight? Possibly, but it's not that original, in fact the other Hunterian museum in London at the Royal College of Surgeons also has specimens of lizards with two tails in their collections and the inclusion of animal specimens alongside human remains is fairly common due to the teaching of comparative anatomy in the last century.

However, the real reason I have brought this specimen to the spotlight talks is that I only recently identified it in a very serendipitous and timely way. I had seen the lizard before, when getting to know the Anatomy Museum but as it was displayed alongside other specimens with malformations I did not pay it much attention as a zoological specimen. Months later when I was conducting a tour of the Anatomy Museum, a visitor pointed out an error on a label on one of the human specimens on the same shelf, so I looked more closely at all the objects to work out what had been mislabelled. It was then that I realized that the double-tailed specimen was the same genus or possibly even species as another lizard in our zoology collection, which I had been photographing earlier in the week for another project.

This is where it gets interesting, the lizard I had been photographing was not just any lizard, but an endemic species, only found in Jamaica. The Jamaican Giant Galliwasp (Celestus occiduus), which is presumed to have gone extinct in the 1800s due to loss of habitat, and invasive rats and introduced mongoose preying on them. There are only a handful of specimens, maybe fewer than 30, in collections in Europe and the USA, so to find a Celestus sp. sitting openly on a shelf was a fantastic moment.

Further investigation of an old register (Reference Code: GB 247 MR 49/4 in the University of Glasgow Archives and Special Collections), written by Prof Allen Thomson, who was head of Anatomy in the mid-1800s, provided a very tantalising clue as to its provenance: "Large lizard (?) The Galawasp from Jamaica given me by Dr Douglas Maclagan 19th Nov. 1853, found in the swamps on the S.W. part of the island, piebald colour much brighter during life as stated by Dr M's correspondent Dr Macfarlane of Montego Bay."

However, I must say I am slightly wary of connecting this record with the specimen, as there is no mention of it having a double-tipped tail. Having said that, there are no other galliwasp specimens in Anatomy, so the odds are high that this entry is talking about the same specimen.

Its discovery was very timely as it was made when the other Jamaican giant galliwasp in The Hunterian was in the process of being repatriated to Jamaica. This lizard had been in our zoology collections since 1888, but as part of the decolonization process and as a way of building relationships, I suggested offering the specimen back to a museum in its country of origin. The reasons being that it was endemic, more than likely extinct (so no new specimens could be collected), but mainly because at that time, there were no known specimens of this species in Jamaica. The repatriation went ahead in April 2024, when curators from Jamaica came for a knowledge exchange visit to Scotland and took the galliwasp back home with them. As we still have the "double-ended tail" galliwasp in the collection, we can continue to tell the tragic story of this species.

Interesting and significant specimens can be hidden in plain sight in many collections, so keep your eyes open and who knows what you may find.