Our Deputy Keeper of Natural History, Dr Emma-Louise Nicholls, gets to know the enigmatic Platypus.
Our Venomous Piece of the Past
We have a number of platypodes (or platypuses if you prefer, but never platypi), however, this one is part of the original Frederick Horniman Collection. That enigmatic accolade means it must have been acquired by our illustrious founder, and prior to the Museum opening in 1906. So in modern social media speak, it’s well old.
We don’t know what the platypus looked like when it was first acquired by the Museum; it could have been either a skin or a taxidermy mount. Either way, at some time in the past the platypus was ‘re-set’ (wording on record card), by the taxidermist Charles Thorpe, into the swimming position that you can see in the image below. The price for this exquisite demonstration of skill was £0 d7 s6. For those who didn’t suffer through the confusing period of decimalisation, £0 d7 s6 means zero pounds, seven pennies, and six shillings, the value of that price today is around £10 (an exact figure is impossible to calculate on the basis we don’t know what year the work was carried out).
We know the specimen is a male as it has a sharp spike, called a spur, on the rear of each thigh. Platypodes* are one of the few mammals that are venomous, and the small amount of venom that can be injected through one of these spurs is potent enough to kill mammals many times their size. I was told by a friend who works in a zoo in Australia that their colleague was once spurred in the arm. Apparently, it was so painful he was pleading with the doctors for his arm to be amputated, ouch! During the mating season the amount of venom a male produces increases, which presumably means one of the main purposes of evolving such potent venom is to fend off rival males and get a girlfriend. In more anthropogenic cases, recent research suggests platypus venom could be used in a treatment for Type 2 diabetes. For which they have frisky platypuses to thank I guess.
They Don’t Have Teeth
Platypodes don’t have teeth in the traditional sense. Their fossil ancestors had teeth but the modern platypus decided the sound of growing their own enamel was reason for concern, and produced coarse keratin pads instead. A mouth full of hair** sounds disgusting, and it only seems to work ‘fairly well’ to boot, as according to a number of sources, platypodes will also scoop up coarse gravel to aid mastication. Perhaps they should have planned it out better before embarking on their otherwise admirable attempt to avoid expensive dental bills.
Platypodes are bottom feeders (legit term), which means animals that feed off of the substrate in aquatic environments. In the case of the platypus, it lives in rivers and uses the receptors in its bill to pick up the electrical signals given off by their prey, which are normally found in the form of insects, insect larvae, worms and shellfish.
They Do Have Teeth
Platypodes don’t have teeth… I wasn’t lying before. However, platypodes are monotremes which means they lay eggs. One of only two mammals to do so, the other being the echidna. As with more traditional egg breaking youngsters like those belonging to birds and many reptiles, for example, the tiny egg-bound platypus has to break its way out of the egg. For this, its ancestry provided it with an egg-tooth on the top of its bill. This tooth is only a temporary facial addition that, once the baby platypus has broken free of its yolky home, will normally be shed within the next two days. The egg-tooth is not a real tooth as ours are, but a sharp, tooth-shaped structure made of keratin, around 0.3 mm high. That may seem ridiculously small but a freshly hatched platypus is only around the size of a kidney bean so any larger and it would probably get neck ache.
These line drawings show the development of the platypus from the day of hatching to five days post-hatching. The egg-tooth can be seen in the first two columns of sketches. The protuberance on the bill in the two right-hand columns represent the caruncle, or fleshy nub, left behind by the egg-tooth. , Image from Manger et al., 1998
* The more I say it, the more you’ll get used to it
** Keratin is the protein that makes up your hair and fingernails
Manger, P. R., Hall, L. S., and Pettigrew, J. D. (1998). The development of the external features of the platypus (Ornithorhynchus anatinus). Philosophical Transactions of the Royal Society of London B 353 pp.1115-1125
Old English Money
Tosatto, D., and Zool, W. S. (2016). Feeding and digestive mechanisms of Obdurodon dicksonii and its implications for the modern Platypus, Ornithorhynchus anatinus. Unpublished. pp.1-12