The platypus is a creature pertaining to an order of small egg-laying mammals unique to Australia, known as monotremes. With a soft rubbery duckbill, able to perceive natural electrical stimuli and venomous foot spurs. Whilst a modern platypus may measure a mere 50 centimetres, between 5 and 15 million years ago its predecessor measured over three feet in length.
This discovery was made after a single ancient tooth was uncovered at Riversleigh in the north-eastern Australian state of Queensland. This discovery bears untold data upon a lineage of animals which have captivated people since their recognition in the late 1700’s. It seems to have taken many years for scientists to accept the existence of the modern day platypus, believing samples were clever duplicates.
Yet Michael Archer of the University of New South Wales unambiguously attributes this most recent find to a previously inconceivable species of extinct platypus. Even with a fragment of a sample, a tooth, Archer might identify this sample “in the pitch black, with the tooth held behind my back” as like its owner, platypus teeth seem to be incredibly unique. Archer went on to claim this single tooth discovered by Rebecca Pian, a PhD student of Columbia University, was adequate evidence of a new species.
The nature of the tooth itself may provide a tantalizing glance into the behavior of this extinct colossus. Marks upon the cusp tips of the tooth indicate heavy, high impact use upon a hard possibly armored organism. Whilst modern day platypuses may prey upon small invertebrates and fish, this creature may have fed on turtles and frogs; these are organisms well documented in the fossil records from the Riversleigh excavation site at the Queensland quarry. The wear marks may likely be caused by its jaw locking around prey items and the compressing of bones and shell, creating a new, maybe almost intimidating persona for the platypus.
This new giant platypus, named Obdurodon tharalkooschild, differs from its evolutionary counterparts in several key elements. Previously, it was assumed the platypus’s evolutionary path followed a simple linear route; one platypus species developed at a time with species displaying a decrease in body mass and a reduction in teeth as time progressed.
However this simple evolutionary model may have to be modified with the addition of a new platypus species, which contrary to previous evidence, might have shared its habitat with another species of platypus. The relative size of this animal punctuates it as an oddity, as it was understood platypuses had already become much smaller at this point, going in opposite to the observed progressive size reduction.
Furthermore, this species evidently possessed teeth, similar to antecedent species and unrepresentative of its time period. Oppose to earlier theories, the platypus’s evolutionary tree may be far more convoluted than previously perceived. This is the first historic example of an “experimental” platypus side branch from its unnaturally linear family tree.
Whilst this side branching may serve to increase the platypus evolutionary tree’s complexity, it is important to ascertain the new species taxonomic position. The platypus may be a evolutionary intermediate species for mammals, and as such its lineage shines a light upon mammalian evolution in general. Yet further research is needed. Geneticists Jenny Graves may be partly responsible for sequencing the platypus’s genome in 2008 and has pointed out a challenge when aiming to determine whether a feature was ancestral to all mammals, or unique to platypuses. And with data for new platypus species limited, more fossil evidence is required to establish how similar, or divergent, this early mammal was to platypuses and mammals in general.
With an increase in scientific interest towards the platypus likened to the same in close primate relatives, to what extent might this benefit conservation efforts towards the platypus?