UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 10, No. 10, pp. 137-164, 8 text-figures Issued February 5, 1917 



RECENT STUDIES ON THE SKULL AND 

 DENTITION OF NOTHROTHERIUM 

 FROM RANCHO LA BREA 



BY 



CHESTEE STOCK 



CONTENTS 



PAGE 



Introduction 137 



Cranium 139 



Mandible 148 



Dentition 151 



Review of Species 157 



Relationships of Genus 162 



Conclusions 163 



INTRODUCTION 



The first remains of the Pleistocene ground-sloth Nothrotherium 

 (Coelodon) were found in a Brazilian cavern by P. W. Lund, 1 who 

 believed the fossils to represent a small Megatherium. Lund later 

 recognized the distinctness of the form and established the genus 

 Coelodon. 2 Material belonging to a young individual subsequently 

 collected by Lund was fully described and compared with other 



1 Lund, P. W., Om Huler i Kalksteen i det Indre af Brasilien, der Tildeels 

 Indeholde Fossile Knokler, Pt. 1, Kgl. Danske Vidensk. Selskabs Skr., 4 Raekke, 

 naturvidenskabelige og mathematiske AfhandL, 6 deel, pp. 207-248, 2 pis., 1837. 



2 Lydekker in ]889 replaced Coelodon Lund by Nothrotherium, stating that 

 the former name was preoccupied. Recently Winge (E Museo Lundii, vol. 3, 

 pt. 2, pp. 136-138, 287-288, pis. 24-25, 1915) has returned to Lund's original 

 designation of the genus. 



The name Coelodon was first used by Audinet-Serville (Ann. Soc. Entom. 

 France, L832, p. 164) for a genus of long-horned, wood-boring beetles (Fam. 

 Cerambycidae) from Senegal. Since Lund did not propose Coelodon for the 

 ground-sloth from the Brazilian cavern until 1839, there is no question as to 

 priority. 



