The Kem Kem Beds, also known as the Continental Intercalaire, span part of the border between Morocco and Algeria. They date back to the start of the Late Cretaceous, a span of at least eight million years from the Cenomanian to the Turonian Stages.
It was only recently that the exploration of North Africa truly began, with the Kem Kem fossils revealing an incredible diversity of extinct life. Many fossils here also make up the livelihoods of the local people.
Because fossils are collected on a regular basis by layman prospectors and vendors, even rare and valuable remains might be lost to science forever.
Three separate formations make up the Beds. The Aoufous Formation is the most well-known and represents the middle of the Beds, roughly 95 million years old. This area is made up of red sandstone, as per Paul Sereno in 1996, one of those who opened up the Global South to many paleontologists. The Kem Kem is the same age as the related Bahariya Formation in Egypt. Today, both lie in the northern reaches of the Sahara Desert but at the time North Africa was cut into pieces by a massive inland sea. This created a number of tidal channels and swamps, an ecosystem not unlike the deltas of Australia’s Northern Territory and the Sunderbans of Bangladesh, much like a mangrove forest.
This environment however, did not contain any traces of mangrove trees, for these had not yet evolved. There were marine-adapted ferns like Weichselia, though. These, and algal reefs, formed the majority of plant communities here. In terms of the faunal life, the ecosystem here had been turned on its head with massive herbivores being a rarity.
There aren’t many sauropod remains from this area. At the time, the rest of the Southern Hemisphere was practically crawling with them. The best-represented sauropod here is Rebbachisaurus. It was a short-necked and ridge-backed relation of the famous Diplodocus and Apatosaurus but only half the size, at a little over 15 meters.
Contrary to earlier reconstructions, these massive, long-necked dinosaurs were more comfortable on dry ground than in the water. With large herbivores in such rarity, the only other logical explanation is that decomposing microbes and other small living things were at the bottom of this food chain. This isn’t as silly as it sounds, for microbial mats, or colonies do occur even today.
Mollusks like marine snails and crustaceans were certainly present as scavengers and detritivores. Feeding off these were numerous groups of fish.
Some of these were eating detritus and algae, and definitely consuming one another too. There were massive coelacanths and lungfish here, as well as huge sawfish up to 8 meters in length. They did not all live in the same place, though for the Kem Kem was still a dynamic, varied environment.
Some might have preferred more sluggish backwaters and bayous while others were fast, pelagic animals in lagoons and deep lakes that fed on plankton and other fish. These fish were eaten by a plethora of other animals. The crocodilians had a few representatives in the form of both toothless plankton-feeders and gharial-like fishermen. The greatest fisher of all though, was Spinosaurus.
Spinosaurus was the largest – or at least the longest – theropod dinosaur in its environment at 15 meters in length but it was far from the tyrannosaur-killer in that awful Jurassic Park sequel. The most recent evidence shows a long-tailed creature with very short legs that probably moved like a combination of a duck and a crocodile. It didn’t just wade into rivers to hunt fish, but instead went swimming after its prey. It must have been rather ungainly on land, having to either trail its tail along the ground, or at the very least, waddle.
Next on the list was Carcharodontosaurus. In reality, this theropod is not very well known, and what we know about it has to come from its relatives. It is one of those other theropods longer than T. rex, growing 13 meters in length. However it was much more lightly built and lanky.
In reality, it probably does not make a difference. It is possible that while it hunted sauropods and other theropods, it also depended on the huge fish of the Kem Kem swamps, maybe almost as much as Spinosaurus did.
The third large theropod is Deltadromeus, and there have been doubts about what exactly this animal was like. It is assumed that the closest relative of this animal was a small, long-necked, probably herbivorous ceratosaur named Limusaurus, from Jurassic China. If this is the case, then maybe it was a fast-running herbivore.
If not, it would have been more generic, a speedy, lightweight predator. It is difficult to know since no skulls of the animal have actually been found.
Two pterosaur genera are known from this formation. The first is Siroccopteryx, a fish-eating anhanguerid. These pterosaurs had very long, eagle-like wings and were experts at soaring over the ocean. The second is Alanqa, a slightly-better known genus.
Alanqa is an azhdarchid. It was, however, not a terrestrial stalker like the rest of its kind. Instead it used the hard knobs in its beak to crush oysters and other shellfish. Both had wingspans somewhere between 4 and 6 meters across. With so many large carnivorous tetrapods, all sense of normality had long since been sapped out of the Kem Kem ecosystem. Fish breed rapidly and en masse, so in a way the base of this food web actually managed to replenish itself quite quickly.
Plus, the numerous predators probably also practiced intraguild predation. Predator guilds are size and weight classes that separate carnivores into their niches but more often than not in nature, members of a certain guild can start targeting members of other guilds.