A New Ammonite Fauna of the Lower Turanian of Mexico 193 



I 



The fossils of the lower Turonian or Salmurian of the Cerro del Macho 

 present a much better material for faunistic comparisons. Already while 

 comparing our species with related ones from other regions we have seen 

 that similar forms are found mainly around the Mediterranean, inclusive 

 of Portugal. Comparing the faunas of the Salmurian in the above men- 

 tioned region, we find that all of them contain certain elements which 

 either do not exist in most other regions or which occur only very rarely 

 there. We shall see later on that this special fauna is not restricted to 

 the Mediterranean but extends also to other parts of Africa and that 

 certain elements belonging to it occur also in Asia and America. This 

 indicates a large extension of the same horizon, but 1 at the present time 

 it is impossible to say if this distribution coincides with that of the same 

 paleontological facies. But before we enter into such a discussion we must 

 compare our fauna with the isochronous faunas of the Mediterranean and 

 other parts of the earth in a somewhat more detailed manner. 



Portugal: We begin with the region of Portugal. According to Choffat 1 

 we find in the lower part of the Turonian (beds with Ostrea columba 

 major) the following cephalopods: 



Puzosia cfr. planulata Sowerby 



Vascoceras Mundae Choffat 



Vascoceras Gamai Choffat 



Pseudaspidoceras cfr. Footeanum Stoliczka 



Neolobites sp. nov. 

 In his middle Turonian we find the following species: 



Vascoceras Gamai Choffat 



Vascoceras Gamai Choffat var. triangularis Choffat 



Vascoceras Mundae Choffat 



Vascoceras amieirense Choffat 



Vascoceras silvanense Choffat 



Vascoceras adonense Choffat 



Vascoceras Grossouvrei Choffat 



Vascoceras Barcoicense Choffat 



Vascoceras Douvillei Choffat 



Vascoceras subconciliatum Choffat 



Vascoceras harttiforme Choffat 



Vascoceras Kossmati Choffat 



Vascoceras ( ?) arnesense Choffat 



iChoffat, Syst. cret. Portugal II. p. 162, 170, 173. 

 Choffat, Especes nouv. ou peu conn., p. 44, 47. 



