Tetrapod Zoology

* Note that Talpanas joins that very annoying list of names where the authorship of the taxon [Olson & James] is different from the authorship of the paper [Iwaniuk, Olson & James]: why do people do this? This makes it look as if naming the taxon is the bit that deserves the credit (a criticism previously made by Landry (2005) concerning the naming of the Kipunji Rungwecebus kipunji), not the production of a paper on it.

So far as I know, only the braincase, posterior part of the lower jaw, tarsometatarsus and posterior part of the pelvis of Talpanas have been described (Iwaniuk et al. 2009). By comparing the measurements of these elements with those of other waterfowl, Iwaniuk et al. (2009) were able to estimate a body mass for Talpanas (692-1072 g, about equivalent to a Northern pintail Anas acuta), and establish how peculiar its proportions were. Its tarsometatarsus was proportionally small, so it was short-legged, and its shape best matches that of heavy-bodied terrestrial waterfowl.

The most interesting features are seen in its braincase [shown here, from Iwaniuk et al. (2009). Scale bar = 10 mm]. It had very small eyes and small optic nerves (and hence poor vision), while the trigeminal nerve (associated with relaying tactile information from the face and mouth) was huge. The nasal cavity was large compared to that of other waterfowl, extending posteriorly (into the region normally occupied by the eyeballs!) to reach the braincase. What's known of the palate suggests that the bill was broad-based, but we don't know anything definite about the shape of the whole bill.

Combined, these features suggest that Talpanas was a small-eyed, flightless, stout-legged duck that relied on smell and tactile foraging. Iwaniuk et al. (2009) concluded that it was a kiwi-mimicking duck that foraged nocturnally, presumably in sediment or leaf litter. The fact that an enlarged trigeminal nerve is also present in platypuses 'raises the intriguing possibility that Talpanas may have relied on more than simple tactile input in prey detection' (p. 66). Larry Witmer tells me that work underway on the skull reveals some exciting further insights... but, alas, no evidence for an electroreceptive ability.

It seems only natural to wonder what Talpanas looked like when alive. The known bits and pieces aren't used by Iwaniuk et al. (2009) to create a skeletal reconstruction or life restoration: despite the fragmentary nature of the remains, enough of the animal is known to produce at least a schematic reconstruction, but you might argue that this would be too speculative an exercise, given that we don't know such things as dorsal column length, bill shape and so on. Purely for fun - it is NOT meant to be taken seriously! - I knocked up the image shown below a few weeks ago. Inspired, Holly Nelson produced the colour picture shown at the very top. Please note that they are not scientifically rigorous life restorations - err, far from it... they're cartoons - and we await the appearance of proper, accurate renditions of this animal.

These pictures could well be criticised for not being weird enough. Should the nostrils be terminal, as in a kiwi? Hanneke Meijer asked why I hadn't fitted the duck out with kiwi-like whiskers, and I'll admit it's possible that the duck had peculiar sensory organs that made it different from other waterfowl. However, my assumption is that it used a hypertrophied, super-tactile bill as its main foraging organ, and I had such species in mind as the Pink-eared duck Malacorhynchus membranaceus.

If you know anything about Hawaiian birds, you'll know that they were catastrophically affected by human hunting and habitat change. About 40 species were made extinct over the last 1500 years, including a variety of spectacular flightless waterfowl. The Talpanas holotype came from Mid-late Holocene deposits about 5400-5300 years old, so the species was presumably killed off during this phase of anthropogenic extinction. We look forward to seeing more information on this fantastic bird, and I apologise to its describers for producing such a laughable and offensive rendition. Any further renditions of Talpanas gratefully received!

One last post on babirusas coming soon, plus I still haven't finished the birthday celebration stuff.

For previous Tet Zoo articles on waterfowl see...

• Pink-headed duck and Red-crested pochard: who would win in a fight?
• The Madagascar pochard returns (again)
• Lo, for I have seen the Meller's duck, and it was good
• Duck humps dog, and other stories from the world of waterfowl sex
• Ridiculous super-elongate, coiled windpipes allow some birds to function like trombones - - or is it violins?
• Harbour seal kills and eats duck
• STOP 'feeding' the ducks
• Attack of the flying steamer ducks
• Meteoroid vs goose... again
• 2007: a good year for terror birds and mega-ducks
• Tet Zoo picture of the day # 10 (on Swan goose)

And, given that kiwi were mentioned here, you might like to check out...

• Yes, it was a kiwi
• 200 years of kiwi research

And for monotremes and electroreception see...

• On electroreception, poisonous ankle spurs, and lots of REM sleep

Refs - -

Iwaniuk, A. N., Olson, S. L. & James, H. F. 2009. Extraordinary cranial specialization in a new genus of extinct duck (Aves: Anseriformes) from Kauai, Hawaiian Islands. Zootaxa 2296, 47-67.

Landry, S. O. 2005. What constitutes a proper description? Science 309, 2164.