Aquans, Avians and Pontopters

The major chunk of Paul's work involved designing a class of flying creatures - "Avians" for want of a specific name - that have the same basic body plan as the Poncedonus. To recap: this plan is basically a five limbed (pentapod) form, with two forelimbs (1&2), two mid-limbs (3&4) and a hind limb (5) which, in some families, is much like a tail.  In the Poncedonus, limbs 1&2 were for grasping prey, 3&4 were for floatation and 5 was for locomotion.  The basic Ceretridon descendant had limbs 1&2 turned into mouthparts, and 3, 4 & 5 for walking (see Act II).

Paul's avians are evolved from fishlike "Aquan" ancestors (as he illustrates) that clearly predate the Poncedonus. The Aquan and the Poncedonus thus have a common ancestor, possibly millions of years in the past whilst Epona was still well frozen in its last Ice Age.  Aquans and Flying Aquans are probably still extant today, but it is the modern Avian form that is best suited as a rival to Ceretridon as a candidate for future intelligence.

Most Avians retain limbs 1&2 as grasping appendages, either for catching prey or hanging from a perch.  Limbs 3&4 have evolved into canards, or "fore-wings" that mainly act as stabilizers and Limb 5 has become a "hind wing" which propels the creature by flapping up and down in a similar manner to the horizontal tail fluke of a dolphin.

Avian wing shapes

Now Paul has experimented with paper models of these designs and they glide very well -- rather better than a birdlike form, in fact.  However, I have found it difficult to picture them in my mind actually flapping since, unlike birds, it involves a motion with a net angular momentum.  Consider a terrestrial bird flapping its wings: both wings beat in a mirror image motion of each other, their angular momenta cancel out, permitting unwavering and stable flight. These Avians, though, pivot their hind wing up and down about the middle of the body, which would result in an undulating, bobbing motion (except when gliding). This takes a while to get used to, but envisaging real alien creatures should tax the imagination!

Various views of an uther (top, isometric, side, front); pose is the "gliding position"

Could they actually work? The more I think about it the more convinced I become that we can really run with these creatures, especially as Paul has provided a choice of variant forms (perhaps the "Concorde" version though is a rather difficult to justify!). This is especially true when one takes into account that the hind wing is ribbed with extensile muscle/skeleton and therefore is not just a crude paddle but can be made to vary its geometry as it beats. This also applies to the smaller fore wings which need not be entirely passive structures.

Del Cotter happens to be working on another five limbed avian form, details of which are tantalizing, but sketchy. Quoting from his email again:

"I will try to put together my thoughts on the osmotic muscle and the avians. I think I can fix the muscle, but the avians will have to be toned down a bit! I have sketched an albatross analogue called a 'Mariner', and am thinking of a smaller relative with a different gliding strategy ¾ like a storm petrel.
They glide on their front wings (which are capable of flapping flight; the details will depend on whether the muscles are compressive or tensile) and when near the water they use their rear fluke (which has developed an oar shape) for propulsion. This rear fluke becomes a stabiliser in free-air flyers, and a monopod in land adapted forms. Both pelagic types feed on the swimming and "flying fish" aquans which are their close relatives..."


A few days later Del returned with:

"I have a sketch of the Mariner's ancestor, and although it's descended (I thought) from Paul Birch's aquans, it looks suspiciously like Poncedonus. I have christened it 'Pontopter'; it migrates annually using a winging round effect.  I would suppose its nearest earthly analogue is something like the salmon. Since its reason for doing this is to migrate across seas at high speed for low effort while avoiding swimming predators, I am not sure if the genus survives the development of flying predators . . .
It could fit into the Poncedonus family tree, but probably not where Geoff Landis put it."

Paul's point about the Avians having a global distribution is well made although their recolonization of the land only seems to have occurred in the Highlands and Fire Island region, along with the Geoff Landis' "hydrofoil" descendants of Poncedonus (see Act I: Fauna).

Ready to find out more?

Birch: Pentapod Anatomy