Geology and Natural History. 403 



Allied to Anchisauripus is another carnivorous form whose foot 

 is more specialized than that of the former in the enfeeblement 

 of the hallux and increase of weight which has rendered the foot 

 flatter and its pads more complex. This creature, Gigandipus, 

 reminds one strongly of the Jurassic Allosaurus, though in the 

 latter the claws were probably more trenchant and the whole foot 

 more efficient as a grasping organ. Gigandipus, known from but 

 one specimen, shows a sinuous caudal trace. The dragging of 

 the tail probably was not habitual, but occurred only when the 

 animal was slowing down before stopping. 



Another abundant genus is Grallator, characterized by very 

 long limbs and small, compact feet without an impressing hallux 

 and with no tail trace. The proportions of length of limbs to 

 those of feet are the same as in the bustards and the forms 

 which made the tracks were probably aberrant carnivores of 

 habits somewhat similar to those of wading birds, possibly feed- 

 ing upon feebler reptiles and amphibians, orxm fish. In consider- 

 ing the probable relationship of this genus to genera known from 

 their skeletal remains, one is reminded strongly of Ornithomimus, 

 a Cretaceous Compsognathoid dinosaur. Grallator comprises for 

 the most part small forms, the smallest species, G. gracilis, indi- 

 cating a creature but two-thirds the size of Compsognathus, the 

 smallest known dinosaur, whose dimensions may be compared 

 with those of the domestic cat. 



Among the habitually bipedal forms, those which never 

 impress the manus, is one group to which the name Eubrontes 

 has been given. It includes larger and heavier forms than 

 Anchisauripus with more blunted claws, but Hitchcock included 

 it with the latter under the name Eubrontes and the later name 

 Brontozoum. The two genera are so different in character that 

 the present author is constrained not only to separate them gen- 

 erically but ordinall}' as well, for the lack of a grasping hallux, 

 the heavy, slow-moving tread, and the blunter claws are surely 

 not carnivorous characteristics, but seem to point rather to an 

 herbivorous habit of life. It may be that instead of being 

 Orthopod or Predentate dinosaurs the Eubrontes represent another 

 group of aberrant Carnivora, which like the condor (Sarco- 

 rhamphus gryphus), because of carrion-feeding habits, did not 

 retain the raptorial claws of its predacious allies. The genus 

 Eubrontes while few as to species contains some of the most 

 impressive forms which are fairly numerous as to individuals. 

 Eubrontes giganteus represents an animal of massive propor- 

 tions and of about twenty feet in length, which is nearly the 

 maximum for American Triassic dinosaurs, though much inferior 

 in size to those of the Jurassic and Cretaceous periods. Dinosaurs 

 beyond question herbivorous in their habits, and hence belonging 

 to the order Orthopoda, are the occasionally quadrupedal forms 

 which, though walking on the hind feet, placed the fore feet on 

 the ground while sitting. This shows that on both manus and 

 pes the claws are short and rounded and no longer subserve a 



