Dermal Boiics of the Skull 



81 



pertaining to this latter type were designated by Mr. Mehely, 

 the discoverer of this interesting osteological feature, as ,,Archaeo- 

 lacertae" , whilst those with na osseous lamina as ,,Neolacertae" . 



As proved by the denominations, Mr. Mehely considered 

 his ,,Archaeolacertae" as a phylogenetically ancestral group, in 

 Opposition to his ,,Neolacertae", which, according to him, ought 

 to represent the modern stage. Mr. Boulenger^^) who criticized 

 Mr. Mehely 's papers, pronounced a contrary opinion: according 

 to him, just the forms bearing an ossified supraciliary lamina are 

 ancestral, whilst those presenting membraneous supraocularies 

 are m.odern types, having degenerated with respect to their 

 cranial ossification. It wouldlead us much too far from our subject 

 to discuss all the different arguments and contra-arguments^^) 

 emitted by these authors in the course of their very interesting 

 polemics. I shall merely confine myself to some evidences offered 

 by the study of the skull. 



All ancestral Vertebrate Types, the Fishes excepted, 

 present a strongly ossified robust endoskeleton, this ossification 

 generally decreasingin the course of phylogenetical development .^4) 

 An Increase of ossification occurs only in rare and special cases, 

 offen through the formation of secondary exoskeletal elements, 

 i, e. secondary dermal bones. This is quite natural, because the 

 higher Classes of Vertebrates, — among which the Batrachians 

 are the direct offspring of Fishes, whilst the Reptiles being again 

 retraceable to Stegocephalous Batrachians, — did not recommence 

 the procedure of their skeletal ossification within each younger 

 phyletical branch. The Fishes, being the first Vertebrates which 

 existed, are quite naturally retraceable to ancestors with a carti- 

 laginous endoskeleton. Now, if we take into consideration 

 the fact that the family Lacertidae, as such, is one of the most 

 recent branches of the Reptilian Stem, the membraneous struc- 

 ture of their skull must be admitted to represent, eo ipso, a secon- 

 dary, i. e. a degenerated feature. It could be presumed, from 

 a purely theoretical standpoint, that ossification may decrease 

 in a branch, and that after this decrease a secondary increase 

 may take place, but in the present case there is no reason or 

 proof at all for such a supposition. The primordial (chondro-) 

 skeleton of the ,,Archaeolacertae** is not a bit more cartilaginous, 

 i. e. less extensively ossified, than in the ,,Neolacertae", and though 

 it would precisely be the unossified (cartilaginous) state of the 

 chondroskeleton and not the ,, membraneous" structure of 

 the primary and secondary dermal bones, which could prove 



Remarks on Prof. L. v. Mehely 's Paper ,,Ziir Lösung der Muralis- 

 Frage", Ann. & Mag. Nat. Hist., XX, London, 1907, p. 39-46. 



See Mehely, opp. ccit., and Boul enger, op. cit. and: Remarks 

 on Prof. L. v. Mehely's recent Contrib. to the knowledge of the Lizards 

 allied to L. muralis, Ann. & Mag. N. H., (8), V, 1910, p. 247 — 256, fig. 5. 



24) Cfr. Bolkay, Addit. to the Foss. Herpetol. of Hungary &e., Mitteil, 

 a. d. Jahrb. d. kgl. Ungar. Geol. R. A., XXI, Budapest, 1913, p. 229. 



Archiv für Naturgeschichte a .t r«. 



1922. A. 7. ^ 7. Heft 



