This one's a little mysterious.
The Slender-snouted Crocodile (Mecistops cataphractus) can be found in the freshwater habitats of central and western Africa. Their distinctive narrow snouts are what inspired their name. This species is one of the least known of all crocodilian species, and research is ongoing regarding the only member of the Mecistops genus. It's theorized that there are two similar but separate species, one localized to central Africa, and one localized to western Africa. Mecistops cataphractus refers to the central African population, but more study is needed for the other theorized species to be classified. When it is classified, however, it would be one of the rarest crocodilians in the world.
Slender-snouted Crocodiles are smaller than the Nile Crocodile, whose range overlaps in some areas. Mature adults can grow up to 13.1 feet (4 meters) and weigh about 507 pounds (230 kg). Particularly large individuals have been recorded to weigh 717 pounds (325 kg). Juveniles are yellow-green in color, with darker markings, and they transition to yellow-brown as they age, and their markings start to fade.
The diet of the Slender-snouted Crocodile consists of prey that its narrow snout makes it easier to catch, like fish, amphibians, snakes, crustaceans and occasionally small mammals and water birds. One of their hunting techniques involves hiding in underwater burrows among the roots of trees, lunging quickly to snag prey. They are very shy of humans, which is part of the reason that so little is known about them. They don't tend to spend time in groups, either, except during the breeding season.
Breeding season of the Slender-snouted Crocodile varies depending on the region, but in general it begins in February. Gravid females will usually have constructed their nest mounds by March, using vegetation and soil. A clutch of 12 to 30 eggs is laid, and the incubation period can be 90 to 100 days. When the mother starts to hear the hatchlings start to chirp, she will start to dig up the nest, helping them to escape it. It is not known how long the mother will tend to her offspring, but she will aggressively come to their rescue if she hears a distress call.
The IUCN lists the Slender-snouted Crocodile as "data deficient," but the little survey data that exists shows that the overall population may be decreasing. They may even be extirpated from areas like Guinea-Bissau, The Gambia and Senegal. Slender-snouted Crocodiles are vulnerable to fishing nets, being easily tangled and eventually drowning in areas where nets are commonly used. They may also be hunted for their hide and meat. Slender-snouted Crocodiles are protected in many of the countries that make up their range, but more research is needed to determine their current status and what kind of conservation action is needed.
Source for all images used in this post.