The
known remains of _Hesperornis regalis_ prove it to have been a
swimming and diving bird, of larger dimensions than any of the
aquatic members of the class of Birds with which we are acquainted
at the present day. It appears to have stood between five and six
feet high, and its inability to fly is fully compensated for by the
numerous adaptations of its structure to a watery life. Its teeth
prove it to have been carnivorous in its habits, and it probably
lived upon fishes. It is a curious fact that two Birds agreeing
with one another in the wholly abnormal character of possessing
teeth, and in other respects so entirely different, should, like
_Ichthyornis_ and _Hesperornis_, have lived not only in the same
geological period, but also in the same geographical area; and
it is equally curious that the area inhabited by these toothed
Birds should at the same time have been tenanted by winged and
bird-like Reptiles belonging to the toothed genus _Pterodactylus_
and the toothless genus _Pteranodon_.
[Illustration: Fig. 212.--Toothed Birds (_Odontornithes_) of the
Cretaceous Rocks of America. a. Left lower jaw of _Ichthyornis
dispar_, slightly enlarged; b, Left lower jaw of _Hesperornis
regalis_, reduced to nearly one-fourth of the natural size; c.
Cervical vertebra of _Ichthyornis dispar_, front view, twice
the natural size; c', Side view of the same; d, Tooth of
_Hesperornis regalis_, enlarged to twice the natural size.
Pages:
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422