. Annals of the New York Academy of Sciences. Science; Science -- New York (State). 230 ANNALS NEW YORK ACADEMY OF SCIENCES puzzling admixture oi' characters, which makes it doubtful whether they should be reckoned as pertaining to the same stock as the other hystrico- morphs. The remaining families, while chiefly South American, are also partly represented in the Ethiopian, Oriental and Holarctic regions. It may be possible, in view of the facts that the European Tlicridomyidae antedate geologically any specialized hystricomorphs, are apparently di- rectly intermediate between the primitive r
. Annals of the New York Academy of Sciences. Science; Science -- New York (State). 230 ANNALS NEW YORK ACADEMY OF SCIENCES puzzling admixture oi' characters, which makes it doubtful whether they should be reckoned as pertaining to the same stock as the other hystrico- morphs. The remaining families, while chiefly South American, are also partly represented in the Ethiopian, Oriental and Holarctic regions. It may be possible, in view of the facts that the European Tlicridomyidae antedate geologically any specialized hystricomorphs, are apparently di- rectly intermediate between the primitive rodent type {Parann/s and its allies) and the hystricomorphs and show the early stages of differentia- tion of several hystricomorph families, that the Ilystriconiorplia are a. T'ertiary ancestors of Eret/iizon t/dae Fig. 14.—Distribution of the true porcupines (llystriculw) and Scic ^Vurld porcupines (Erethisontidw) The HystrlcldiB appear to be of Palaparcfic dispersal, the Erethizontldae are apparently of Neotropical origin. group of Holarctic origin which has spread into all the southern conti- nents and specialized independently on parallel lines. But their entire absence from the recorded North American Tertiary is then explainable only by the defective record, and our knowledge of Xorth American Ter- tiary rodents is so extensive that I should hardly regard this assumption as justifiable. The fact that the highest and most specialized types are South American necessarily involves the idea that that continent has been the most important center of their later development and 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 New York Academy of Sciences; Casey, Thos. L. (Thomas Lincoln), 1857-1925; Van Ingen, Gilbert, 1869-; Poor, Charles Lane, 1866-; Hovey, Edmund Otis, 1862-1924; Tower, Ralph
Size: 1773px × 1409px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1879
