THE LIFE OF MAAMALALS 
enlarged as the animal grew. As some of these glyptodons, 
which fall into several genera, had shells several feet long, the 
weight carried was relatively enormous. Consequently the legs 
and feet, especially those of the hinder pair, are short and mas- 
sive, with the soles planted flat and firm, and ‘‘nearly the whole 
of the vertebra are welded together so that a large portion of 
the backbone forms a continuous solid tube.”’ The head is 
protected by a bony helmet. The tail in most species was nearly 
as long as the body, and its vertebree also, as the animal attained 
to full size, united into a slender hollow cone armed or orna- 
mented with rings of spikes and knobs, ‘“‘forming a protective 
case against which little short of a steam hammer would have 
been of any avail.” Woodward® gives a fine figure of this 
armor. 
None reached so great a size or so bizarre an aspect as did 
the club-tailed glyptodon (Deedicurus) of Patagonia. In this 
monster, sometimes twelve feet in total length, the 
carapace is humped in outline and each picce in its 
mosaic is rhomboidal in form, and pierced with from two to five 
large circular holes. Woodward" considers these simply the 
passages (foramina) by which blood vessels and nerves reached 
the surface layers of the skin; but Dr. Lydekker regards them, 
from the analogy of the living hairy armadillo, as the exits of 
large bristles or quills, making the whole animal look like a 
gigantic porcupine. He says: — 
Dedicurus. 
“Still more extraordinary is the conformation of the huge tail, which 
had a length of about five feet. At its base this appendage was encircled 
by about half a dozen double bony rings, nearly as large at the base as the 
iron hoops in the middle of an ordinary beer barrel, their component plates 
being pierced by the aforesaid holes for bristles. The whole of the termi- 
nal half of the tail is formed by one continuous piece of hollow bone, which 
. .. is almost as much as a man can lift. Starting at its base in the form of 
a nearly cylindrical tube this sheath rapidly expands at the sides, and be- 
comes flattened on the upper and lower surfaces, until at the tip it finally 
assumes the form of a depressed, flattened club, which would have formed 
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