WI: Dinosaurs survived on Madagascar

[History Learner]

James E. Fassett of the U.S.G.S has been producing very compelling evidence for Paleocene dinosaurs in the Ojo Alamo Sandstone of the San Juan Basin in New Mexico since the early 2000s. Fassett is of the belief that some Dinosaur species continued on as late as 64.5 Million years ago, which is about 1.5 Million years after the K-PG Impact. Outside of Fassett's research, there has been some evidence for the same in Australasia and in China, there has been the discovery of the Qinornis, a non-neornithine ornithuran from 61 Million years ago despite the previous belief that they had all died out during the K-PG Impact. Interestingly, both the New Mexico and New Zealand arguments lines up with evidence concerning the rising of mammals at the start of the Paleocene. My personal interpretation is that, with their populations heavily devastated by the K-PG Impact, the relic population of Dinosaurs simply failed to proliferate in time before the Mammals took their ecological niches, ultimately outcompeting and thus dooming these Mesozoic survivors.

So what does this have to do with anything? We know for a fact that Madagascar had several extant Dinosaur species and its relative isolation as an island meant it was hard for Mammals to reach it. Existing evidence suggests that there was only four separate waves of invasive species since the K-PG Impact, which has resulted in the extremely unique fauna of the island today that cannot be found elsewhere. This relative isolation would thus make the island a prime candidate as a "Lost World" of surviving Dinosaur fauna, enabling the plucky survivors to successfully repopulate their island and thus maintain their environmental niches instead of being displaced by mammals.

So, as the Austronesians come to settle Madagascar around 350 BC - 550 AD, they find an island predominantly ruled by dinosaurs, with mammals playing a more background roll since they can only dominate certain ecological niches. In particular, the Rapetosaurus-the late Cretaceous sauropod species that dominated the island-has survived relatively unchanged physically but has become socially-sophisticated as a result of an evolutionary arms race with the descendants of Rahonavis, who have evolved into terror bird like predators that replaced the now extinct theropod Majungasaurus. Outside of the explicitly dinosaurian fauna, Simosuchus has also survived and has grown in size to take the place Hadrosaurs and like took elsewhere.

Spoiler: Rapetosaurus, physically unchanged for the most part but now with Elephant-like herd defensive mechanisms

 

[Charles EP M.]

Madagascar would be the greatest country on Earth.

Beyond that, humans would still stick around their and form civilisations - which would be completely different to OTL because of the completely different ecosystem they have to work with but trying to figure out what that looks like is probably a fool's errand - which the Arabs and later Europeans will run into, and go "wow there's some weird monsters on that island". It'll be famous for its unusual 'dragons' and they'll end up in foreign countries as gifts for leaders to gawp at.

The field of paeleontology is completely warped. When we start finding dinosaur fossils, we'll have a better idea of what they are and what they might look like. (So Iguanodon, Megalosaurus etc still have the wrong look in old paintings and statues but different wrong looks) We might be less interested in them because they're no longer lost monstrous beings but instead something we know, but it'll still be considered a big deal that dinosaurs used to live everywhere and not just in Madagascar.

 

[Gary Oswald]

Mega fauna almost always get hunted to extinction by humans. Isn't the most likely outcome that the malagasy eat them all prior to first european contact?

 

[History Learner]

Mega fauna almost always get hunted to extinction by humans. Isn't the most likely outcome that the malagasy eat them all prior to first european contact?

The Rapetosaurus would be about the size of the Asian Elephant and the social sophistication-which I deliberately added for this purpose (besides really being inspired by the book in question)-would in theory enable it to be domesticated the same way the aforementioned mammal was. Such, I would hope, would let it flourish and survive in service to the new Human population of the island. Beast of Burden Sauropods could be used to plow fields as well as to clear forests out for new farmland, via them eating or crushing down everything in an area. Besides this being more sustainable than slash and burn methods of agriculture, it comes with the added bonus of the Sauropods producing a natural fertilizer.

When I originally came up with this idea, I was thinking how this could translate into a much higher Malagasy population on Madagascar could allow them to fight off Bantu migration efforts later on, not only due to their high population density affording greater wealth and manpower, but also the tactical advantage of War Dinosaurs in the vein of War Elephants. Rule of Cool, definitely, but still awesome to think about, at least to me personally.

 

[Thande]

Mega fauna almost always get hunted to extinction by humans. Isn't the most likely outcome that the malagasy eat them all prior to first european contact?

The interesting consequence of that for evolutionary theory is that A Big Deal in the popular imagination (if not necessarily among scientists) was the question over whether dinosaurs were truly extinct, i.e. could it be that such a dominant group could completely have vanished, or whether they still stuck around in the Brazilian rainforest somewhere (as was seriously advocated I think into the 20th century).

There's a big perpetual difference between 'died out millions of years ago' and 'was around at the same time as moas and was explicitly killed off due to human activity'.

It's a bit like the historiographic thing I'm trying to do in LTTW (probably not that plausibly but still) of 'dinosaurs? oh you mean those big archaic toothed birds that died off so now we only have small birds, that wasn't that big or dramatic a change and doesn't say anything that significant about paleontology' due to the bird-like features being spotted sooner.

 

[History Learner]

On the other hand, if the dinosaurs of Madagascar die out in the last 2,000 years or so due to Human predation, we could successfully bring them back ala Jurassic Park since the DNA hasn't degraded that much. It'd be as realistic as Wooly Mammoths coming back.