Terra Nova #40 Cascade Raptorfly

So, this is a speculative evolution project, while many aspects of this come from extant and extinct species, this animal does not exist (as far as we know). The general setting is Terra Nova, a hypothetical India sized piece of land that fragmented off of Gondwana (Africa, Australia, South America, India and Antarctica) in the Cenozoic Period. Terra Nova is in the tropical latitudes within the Pacific Ocean and has a mixture of rainforests, dry scrub, grassland, wetland, and montane habitats.

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Cascade Raptor Fly (Pterydrakus cascadum)

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Odonata

Family: Enedraidae

Genus: Pterydrakus

Species: cascadum

Described: Gould (1966)

When initially discovered, the raptor-flies, were thought to be the nymphs of the plunge pool damselfly (Thaumatoneura ripariovenator), and it wasn’t until the species was raised in laboratory conditions. This retention of neotenal features, was enough to create a new family that would contained the raptorflies, and resulted in a taxonomic reshuffling of Terra Nova’s dragonfly species, leading a glut of species assigned to this family, with a second review removing all but thirteen species. While the raptorflies were unique to Terra Nova, and fairly common where present, their dispersal across the island continent was limited, usually relegated to sinkholes, cave mouths and tepuis due to competition with the neoeurypterids, a group of predatory amphipods, that filled the same niche as these insects.

One of the smaller raptorflies, reaching a body length of 12cm, the cascade raptor fly was also the most common, found behind every waterfall in the Oni Mountains and Lumina Mountains, with multiple insects often present on a single waterfall. Similar in appearance to more conventional dragonflies, the cascade raptorfly was a grey insect with a series of feathery gills running along the flanks of the insect. As the cascade raptorfly reached their fifth instar, signs of sexual dimorphism began to become apparent in the species, with female raptorflies becoming a saffron gold colour and an adhesive sucker on the rear of the abdomen, while male raptorflies became a ruddy red colour, and developed a second set of mandibles. While both sexes were the same size in the first four instars, males began to grow larger than female raptorflies from their fifth to seventh instar stage, when the insects reached sexual maturity.

Cascade raptorflies were active predators, traversing across the face of the rock face looking for prey. The insects were not picky on what they fed on, although the prevalence of flat-shelled limpets (Stimulator terranovum) behind Terra Nova’s waterfalls meant they were the most common target, with the raptorflies snipping off the snail’s eyestalks with their mandibles. Other waterfall dwelling animals such as the waterfall fisherman (Cryptotora minimus) and swimming bristletail (Macropsontus fluvium) were also fed upon, as were smaller cascade raptorflies. While predation was usually limited to their own species, adult plunge pool damselflies and white capped dippers (Cinclus leucocephalus) would fly through the waterfall to snatch the insects off the rocks. When threatened, cascade raptorflies could propel themselves off the rock face, using a jet of air pulsed through their abdomen to get away from terrestrial predators. When falling to the plungepool below, the raptorfly could experience a fluctuation of up to 20 G Force and -20 G Force before landing.

The different instars of cascade raptorfly typically portioned themselves in different parts of their habitat, with later and larger instar stages higher up the waterfall. On reaching their seventh and final instar, male cascade raptorflies would stake territories where they would flick their gills out to attract females. These displays often caused other male raptorflies without territories to challenge them, with males locking their secondary mandibles in attempt to push each off the cliff wall. Larger males didn’t always have the advantage as they typically moved slower allowing smaller males to bite off their gills. The development of the secondary mandibles fused the primary mouthparts open, meaning adult males who successfully bred starved to death, unable to feed upon reaching sexual maturity. Regardless of the outcome, defeat likely meant falling to the plunge-pool below with the inability to return to the breeding altitude. Mating between males and female raptorflies was traumatic for the female, with the males’ claspers chewing the females gonopore closed after transferring sperm to her, before she was tossed off the cliff face to avoid other males mating with her. As the eggs developed, pressure on the closed gonopore caused the rear abdomen of the female raptorfly to swell and later snap off, the sucker anchoring the abdomen and eggs to the cliff wall, as the rest of the animal perished.

Picture References

1: e1.jpg (750×543) (bp.blogspot.com)

If you have any recommendations for Terra Nova’s fauna and flora please leave a suggestion, and if you want to take part with this ‘New World’s’ exploration, send me a message.

@cbishop, @yejj, @whathappened and @arctika

Don't go chasing waterfalls lest the raptorfly strike...

What an interesting looking raptorfly, cool design. No worries on the waterfall front haha the biggest one I've ever seen is the mini ones at my local park, it's about 4 feet perhaps 5. My dad had a cool video of a slider swimming near it about 30 feet away from the land, he fell over it into the next lake. We kind of have two interconnecting lakes at this park. I've only seen dragonflys the standard one with the long tail.

@arctika: Just remember that while a lot of the biology is coming from actual animals, raptor flies are just speculative.

I always remember visiting my first big waterfall it’s pretty impressive and you don’t forget it, especially if you come from a very flat country like me.

Despite that the Netherlands has lots of different dragonflies; chasers, darters, skimmers, hawkers and more. They are very pretty until you see one rip the wings off a butterfly or another dragonfly and then you realise they are predators that are largely changed for almost 300 million years.

Yeah biology was interesting back in school, Earth science was alright.

I find waterfalls oddly therapeutic if that makes sense, my folks when they were younger went to Niagra Falls years ago they said it was nice.

I see, yeah I guess everything has to eat. They always hang around when we go fishing.

@arctika: As an ecologist I sit in the middle, skewing more towards biology but there is certainly some earth science I need to take into account.

No the waterfall thing makes sense unless of course you are heading down one.

The nymphs are worse...

Yes it did inspire the jaws of the Xenomorph from the Alien forms. A big dragonfly nymph will be feeding on tadpoles, small fish and other insects for up to three years until they emerge as winged adults.

@sundown89: That makes sense given your job, I'd imagine it's beneficial to have that overall general knowledge of both.

Yeah for sure, especially smaller ones they have that calming effect. Ha, yeah I wouldn't want to be in that situation even if you do always see people falling over ones in movies and living somehow lol.

I can totally see that, I was about to say looks like something out of a sci fi flick or alien. Damn that's a while up to 3 years before they get wings?

@arctika: It's an organ named a pharyngel jaw and was the basis for the second jaw in this little gem of pop culture.

That three years is nothing, the pharaoh cicada takes seventeen years to reach adulthood, emerging in a swarm of billions for a seventeen day orgy of screaming and mating.

Nice ^ Oh I definitely see that inspiration. I'm personally more team Predator but the Aliens are interesting. Oh yeah that's a good point. We have them here those cicadas a few years back the 17 year old ones spawned. That's crazy how it takes them over a decade to resurface.

@arctika: I can link the issue where Imp covered this species where she goes into why its tied to prime numbers and prolonged glacial exposure in the past.

Oh ok sure if you want, but if you can't find it no worries.

@arctika: Nah you’ve just given me something to do on the train into London.

Oh well that's good lol. On a train to london? You don't play your DS or mobile game or something to kill time? Maybe you're not into games not sure. I don't know if you're a gamer or not but if not all good.

@arctika: Nah it was only a half an hour ride in and it gave me time to go over the SHE Plan, contact my survey second, check the Site Map for where I was going all to so 90s northern soul from the Stone Roses.

But yes I do game on occasion, but it's usually not long sessions due to work and other commitments though.

@sundown89: Ohh onl half hour yeah then probably not worth it lol. That makes sense then. Yeah games definitely take time and investment so if you have a busy life that can be difficult to balance. In the past I've had 2 jobs and classes, that was definitely a pain for free time.