Mesozoic
Triassic
A relative of Sclerothorax that has an even bigger hump of elongated neural spines. Sclerothoracidae.
A Triassic horseshoe crab which has backswept, bull-like cephalic horns. Austrolimulidae.
Bird-like, bipedal sphenosuchian, with a beak-like mouth. Sphenosuchia.
Termite-eating cynodont, converging on anteaters and echidnas. Chiniquodontidae novis.
Large dicynodont with a rhinoceros-like horn. Kannemeyeriidae.
Giant rauischian that converges on carnivorous dinosaurs in being an obligate biped, 9 meters long. Rauisuchidae.
Stem-pterosaur with incipient flight adaptations. Ornithodira.
Jurassic
Relative of Chilesaurus, which is as long as 6 meters, with a covering of pangolin-like scales, derived from primitive feathers. Tetanurae.
An ammonite which adheres to eachother in large clusters to form passively floating colonies. Kosmoceratidae.
Large carnivorous prosauropod, Anchisauria.
Ichthyosaur which is adapted to filter feed like a whale, using its teeth as a filter. Stenopterygiidae novis.
Thyreophoran which is covered in large pointed spines, much like a porcupine. Basal Thyreophora.
A carnivorous dinosaur which kills prey with sabre-like front teeth. Ceratosauridae.
Venomous compsognathid coelurosaur, having channelled fang-like teeth. Compsognathidae.
Theropod which has three bony crests instead of 2 or 1. Proceratosauridae.
A relative of Pterodactylus that is specialized for probing the sediment in search of invertebrates. Pterodactylidae.
Cretaceous
A repenomamus-like mammal which reaches the size of a large lynx. Gobiconodontidae.
A loosely coiled Ammonite that has a ripsaw-like arrangement of ornamentation on its shell. Ancyloceratidae.
A relative of Dolichosaurus that has a laterally flattened body and tail, as with many modern sea snakes. Dolichosauridae.
A short-necked Rebbachisaur with an elongate, horse-like face for grazing on low stubby growth such as ferns. Rebbachisauridae.
A giant relative of Vinctifer, maybe 8 meters long, which inhabits the southern ocean, filling a niche that is filled elsewhere by fish like Bonnerichthys. Aspidorhynchidae.
Appalachian tyrannosaur, which has large raptorial arms, and reaches up to 10 meters long. Tyrannosauroidea.
Mosasaur which grubs in the mud for invertebrates using its sensitive lips, which contain mechanoreceptors. Halisaurinae.
A relative of Hoploparia which has differentiated large and small claws much like a fiddler crab, for courtship purposes. Nephropidae.
A deep-sea Pycnodont fish which is almost completely scale-less, and has silvery skin. Pycnodontiformes.
A Multituberculate with clear adaptations of the lower limb, towards a hopping mode of locomotion. Djadochtatheriidae.
A mid-sized Titanosaur, which is extremely robust proportionally for its size. Lithostrotia.
A Lambeosaur which has a hollow crest bigger than any other. Lambeosaurini.
A long-legged terrestrial Enantiornithine that behaves much like a seriema or secretary bird. Enantiornithes.
A Notosuchian with limb anatomy strongly adapted for cursorial movement. Notosuchia.
An insular Multituberculate which is adapted to prey upon various smaller animals including vertebrates. Kogaionidae.
A primitive ceratopsian which is mainly carnivorous in its adaptations. Leptoceratopsidae.
Medium-sized duckbill, which is adapted to a moose-like, water-plant eating lifestyle. Saurolophinae.
Ceratopsian which has one large nose horn, and very little other ornamentation. Centrosaurinae.
Hawk-like enantiornithe with large raptorial feet and claws. Avisauridae.
Noasaur which spends much of its time underground, like a badger. Noasauridae.