| abstract
| - Squalicorax was a predator, but also scavenged as evidenced by a Squalicorax tooth found embedded in the metatarsal (foot) bone of a terrestrial hadrosaurid dinosaur that most likely died on land and ended up in the water. Other food sources included turtles, mosasaurs, Ichthyodectes and other bony fishes and sea creatures. Squalicorax teeth are both abundant and readily identifiable to genus, even when damaged or water-worn. Having a worldwide distribution, their fossil record includes skeletal remains of S. falcatus, pristodontus and kaupi as well as isolated teeth and vertebral centra. They are placed in the family Anacoracidae, but there isn't unanimous agreement as to the order to which this family should be ascribed. Cappetta (1987: 109-110) provided his reasons for choosing Lamniformes. Shimada & Cicimurri (2005:256-57) included a good overview of this topic, but found no definitive characteristic; they concluded by citing Compagno (1988:404) - Squalicorax was a lamnoid with carcharhinoid-like adaptations. Squalicorax apparently also scavenged, a feeding mode that has earned them the name "crow sharks" in some circles. Paleontologist David Schwimmer and his co-workers have found direct evidence of Squalicorax scavenging, including a decayed mosasaur vertebral centrum with an embedded Squalicorax tooth and many tooth-scarred tetrapod bones. Recently, Schwimmer found a fossilized Squalicorax tooth embedded in a metatarsal (foot) bone of a juvenile hadrosaur (duck-billed dinosaur). Schwimmer speculates that Squalicorax may have relied on scavenging to provide much of its diet and that competition from predatory marine reptiles may have forced these sharks to scavenge carcasses of large creatures - including those of terrestrial animals that somehow ended up in the water, such as the hapless hadrosaur whose remains he found. This may be stretching the fossil evidence a little too far, as remains of fish prey are far more delicate and rarely preserved than those of tetrapods - and most sharks (including the super predatory Great White) will scavenge, given the opportunity. According to Shimada, another species of Squalicorax, S. falcatus, scavenged its larger cousin, Cretoxyrhina mantelli. Other food items of S. falcatus include turtles, mosasaurs, the mackerel-like Ichthyodectes, and the swordfish-like Protosphyraena. Shimada suggests that in their broad-spectrum diet, Squalicorax resembled the modern Tiger Shark (Galeocerdo cuvier). In any case, little else is known about Squalicorax. Even having articulated remains with which to work, paleontologists are uncertain how Squalicorax is related to other lamnoids.
- Squalicorax is a genus of prehistoric shark that lived during the late Cretaceous period.
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