. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 302 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY adapted from Patterson and Kragiievich (ms.). Deseadoniys seems to be ancestral to the comparatively specialized Adelphomys group, composed of the Santacrnzian Adelphomys and Stichomys and an undescribed Colhuehuapian genus, but not including Pro- tadelphomys. The molars of Deseadomys are actually higher crowned than those of the Colhuehuapian Protacaremys and Prospaniomys. These last are sufficiently similar to suggest that their common ancestors may have lived in Deseadan
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 302 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY adapted from Patterson and Kragiievich (ms.). Deseadoniys seems to be ancestral to the comparatively specialized Adelphomys group, composed of the Santacrnzian Adelphomys and Stichomys and an undescribed Colhuehuapian genus, but not including Pro- tadelphomys. The molars of Deseadomys are actually higher crowned than those of the Colhuehuapian Protacaremys and Prospaniomys. These last are sufficiently similar to suggest that their common ancestors may have lived in Deseadan time. The primary radiation of the Echimyidae was evidently in progress PROECHIMYS- DACTYLOMYS ECHIMYS SPANIOMYS ADELPHOMrS EUMYSOPS GR GROUP GROUP GROUP GROUP SANTACRU7IAN ^ COLHUEHUAPIAN PROTADEL- PHOMYS DESEADAN PROTACAR-- EMYS SPAN!OMYS STICH- ADEL- â ? t OMYS PHOMYS /' DESEADOMYS. OGTODONTIDAE Fig. 3. Tentative phylogeny of the Oligocene and early Miocene Echi- myidae. during the Deseadan and presumably had begun not long prior to it. Derivation from the primitive octodontid stem is clearly indicated. The Colhuehuapian Eoctodon Ameghino is neither valid nor an octodontid. The type species, E. securiclatus, is a synonym of Protacaremys prior and the larger E. crassiuscidus is a synonym of Prospaniomys priscus. Both these forms are echimyids. The Santacrnzian Spaniomys is highly variable, and Gyrignophus complicatus and Graphimys provectus appear to have been based on extreme variants of 8. modestus.^ 5 J. L. Kragiievich (;)7. p. .37) believes the "Eumi/gops group" (cf. Fig. :'.) to be part of the subfamily Heteropsoniyinae Antbony. The Pliocene genera /'ronthvnira and Prongiiti of Ameghino cannot be separated from JUivn/KOi)-^.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original
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