344 THE BOOK OF THE ANIMAL KINGDOM 



skeleton from Cape Colony, and exhibited in the Natural History 

 Museum in London. It has the appearance of a huge pug-dog, its 

 length being about nine feet. Its teeth are quite small and indicate 

 a herbivorous habit. 



The JURASSIC rocks, taking their name from the Jura Mountains 

 and attaining a thickness of some 5,000 feet, are noted for their 

 fossil remains of Great Reptiles as well as for the large number of 

 Ammonites and Belemnites they contain. 



The CRETACEOUS system, so called on account of its chalk (Latin, 

 creta), includes rocks of 2,500 feet in thickness. Its fossils indicate 

 land occupied by forests of trees akin to ferns and known as Cycads. 

 These forests provided home and food for huge Reptiles called 

 Deinosaurs (Greek, deinos, terrible; sauros, reptile). 



The TERTIARY or CAINOZOIC Epoch includes the Eocene, Oligo- 

 cene, Miocene and Pliocene rocks. 



The EOCENE rocks, some 800 feet thick, are so named because 

 therein we find fossils of living species of shells to the extent of 

 about three per cent. The name is derived from the Greek eos, 

 dawn, and kainos (cene), recent, and it therefore indicates the dawn 

 of recent species. 



The OLIGOCENE (Greek, oligos, few, and kainos, recent) rocks 

 contain a larger number of living species of shells, although they are 

 still comparatively few. These strata are estimated at a thickness of 

 about 600 feet. 



The MIOCENE (Greek, rheion, less, and kainos, recent) strata 

 bear remains of even more living species of shells, but they are 

 less numerous than the extinct species. The Miocene formations are 

 said to be about 1,000 feet in thickness. 



PLIOCENE rocks are so called because they contain a large 

 proportion of fossil remains of shells that still exist. The derivation 

 of the term is from the Greek pleion, more, and kainos, recent. 

 Pliocene strata are the highest and most recent series of rocks of the 

 Tertiary Epoch. They approximate a depth of some 250 feet. 



The Tertiary or Cainozoic rocks bear fossil remains of absorbing 

 interest, remains which indicate the preponderance of mammals 

 during the epoch which they represent. The higher strata of the 

 Primary rocks yield remains of great amphibia; the Secondary or 

 Mesozoic rocks bear fossils of great reptiles, and the Tertiary forma- 

 tions are noted for the remains of great mammals which they 

 preserve. The reader will note the ascending scale of life-forms as 



