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XIII. — On the Bones of Birds discovered in the Strata of Tilgate 

 Forest, in Sussex. 



By GIDEON MANTELL, Esq., L.L.D., P.R.S, &c. 



[Read June 10, 1835.] 



IHE remains of birds are so seldom found in a fossil state, that a notice of 

 unquestionable relics of this class of animals, however imperfect, cannot fail 

 to be interesting to the geologist and comparative anatomist. Mr. Lyell has 

 well remarked in his Principles of Geology*, that it might readily have been 

 anticipated, that the fossil bones of birds would be of rare occurrence, since 

 the power of flight possessed by these animals, preserves them from many 

 casualties by which quadrupeds are destroyed and imbedded ; and that even 

 when birds are drowned, or chance to die on the water, the tubular structure 

 of their bones, and their feathery coverings, would generally occasion them 

 to float on the surface, until their carcases were devoured. We find, ac- 

 cordingly, but very few authenticated examples of fossil birds, certainly none 

 (with the exception of those which it is my present purpose to describe) that 

 can be referred to strata of an earlier period than the gypsum beds of the 

 Paris basin f. It is true that the thin fragile bones which occur in the slate 

 of Stonesfield were formerly assigned to birds J, but all these are now known 

 to belong to Pterodactyles. 



Soon after my attention was first directed to the fossils of the Wealden of 

 the south-east of England, I discovered in the strata of Tilgate Forest, several 

 bones of such extreme tenuity as could have been required only by animals 

 intended for flight, and some of these, from their close resemblance to the 

 tarso-metatarsal bones of certain Grallce or waders, I was induced to refer 

 to birds§. But when the correctness of the opinion of the late Mr. Miller, 

 that the Stonesfield bones belonged to Pterodactyles, was established, it was 

 naturafly conjectured, that the fossils from Tilgate Forest might also have 

 been derived from flying reptiles; and Dr. Buckland expressed a doubt 



* Principles of Geology, 5th edition, vol. iii. p. 230. 



t Oss. Foss., 5me edit. torn. iii. p. 303. + Geology of England and Wales, p. 208. 



§ Geology of Sussex, 1822. Fossils of Tilgate Forest, 1827. 



