“Horns” seem to have convergently evolved multiple times in crocodiles over the last few million years, including in a couple of living species. These triangular crests are formed from the squamosal bone, just above their ears, and tend to be a sexually dimorphic feature used in territorial displays between males, serving to make them look bigger when they arch their necks.
But there’s another horned crocodilian known from much earlier in the Cenozoic – and this one was an alligator!
Ceratosuchus burdoshi lived in Colorado and Wyoming in the western United States during the late Paleocene and early Eocene, about 57-56 million years ago. It was a fairly small alligator, around 1.7m long (5’6″), with a broad snout featuring sharp teeth at the front and blunter teeth further back – an arrangement that suggests it was a generalist predator eating a variety of small prey, using those teeth to first grab and then crush whatever it managed to catch.
It also had large blade-like osteoderm armor on the back of its neck, which may have been arranged in line with its “horns” to make its visual displays look even spikier.
Did you know some crocodiles have “horns”?
Formed from the corners of the squamosal bone at the back of their skulls, just above their ears, these structures are seen in living crocs like the Cuban crocodile and the Siamese crocodile, as well as some fossil species.
But perhaps the most impressively-horned croc was Voay robustus here.
Voay lived on the island of Madagascar during the Late Pleistocene and Holocene, between about 100,000 and 2,000 years ago. At about 5m long (16′5″) it was similar in size and build to a large male Nile crocodile – but despite this resemblance its closest living relative is actually the much smaller dwarf crocodile.
It had a fairly short and deep snout and chunky limbs, adaptations associated with a more terrestrial lifestyle that suggest it was specialized for hunting its prey on land rather than just at the water’s edge.
Much like modern horned crocodiles its particularly prominent horns were probably used for territorial displays, and may have been a sexually dimorphic feature with big mature males having the largest examples.
Voay’s disappearance just a couple of thousand years ago may have been the result of the arrival of human settlers on the island, either from being directly hunted or due to the large native species it preyed on also going extinct around the same time.