Name:
Doedicurus
(Pestle tail).
Phonetic: Day-dih-core-us.
Named By: Hermann Burmeister - 1874.
Classification: Chordata, Mammalia, Xenarthra,
Cingulata, Glyptodontidae.
Species: D. clavicaudatus (type).
Diet: Herbivore.
Size: Average 3.5-3.6 meters long, larger
individuals up to 4 meters long.
Known locations: North and South America.
Time period: Pleistocene.
Fossil representation: Many known specimens.
With
a length of four meters Doedicurus is easily one of
the larger members
of the glyptodonts, armoured herbivores that are related to modern
day armadillos. Like other glyptodonts, Doedicurus
had an armoured
shell made from osteoderms that grew to surround its body. This shell
was most strongly fixed around the pelvis, with the shoulders
retaining a degree of independent mobility while still being covered by
the shell. A secondary hump is also present on top of Doedicurus’s
back, and this has been suggested by palaeontologists as a fat
reserve similar to a camels. While Doedicurus
could not withdraw its
head into this shell, the head still had bony armour growths that
afforded Doedicurus additional protection from
predators.
The
tail of Doedicurus also had an additional covering
of bone that was
more flexible than the main shell. The really special adaptation of
the tail however was the spiked club on the end, with the flexible
armour covering of the upper tail allowing Doedicurus
to to swing
this club from side to side. It is the removal of these spikes that
led to the name Doedicurus, or ‘pestle
tail’, as without them,
the club seems to be covered in pestles.
The
tail club of Doedicurus seems to have been for
intra-specific combat
between two competing individuals, possibly males looking to attain
mating rights over a female. Strong evidence for this behaviour comes
from damage on the body shells of some Doedicurus
specimens that match
the general size and structure of Doedicurus tail
club spikes. The
scenario would see two Doedicurus squaring off
against each other in a
side by side head to tail orientation, and then hitting each other in
the sides of their bodies with their spiked clubs.
An
additional theory for the tail club has been that of predator defence,
although when examined in more detail it seems unlikely that a single
Doedicurus could have effectively used this club
against a predator.
The main problem here is that because of the large body shell,
Doedicurus could not see behind itself to target an
attacking
predator. An alternative could be if Doedicurus
lived in groups and
when attacked clustered facing together and all sweeping their tails in
unison to create an intimidating living wall of armour and swinging
clubs.
Further reading
Contributions to a knowledge of the Fossil Vertebrates of Argentina.
Part II. 2. The extinct edentates of Argentina. Anales del Museo de La
Plata. - Paleontolog�a Argentina 3:1-118 [C. Jaramillo/J. Carrillo] -
R. Lydekker - 1894.
- Tail blow energy and carapace fractures in a large glyptodont
(Mammalia, Xenarthra). - Zoological Journal of the Linnean Society -
126(1): 41–49. - R. McNeill Alexander, R. A. Farin & S. F.
Vizca�no - 1999.
- The sweet spot of a biological hammer: the centre of percussion of
glyptodont (Mammalia: Xenarthra) tail clubs. - Proceedings of the Royal
Society B. 276 (1675): 3971–3978. - R. E. Blanco, W. J. Washington
& A. Rinderknecht - 2009.
- Ancient DNA from the extinct South American giant glyptodont
Doedicurus sp. (Xenarthra: Glyptodontidae) reveals
that glyptodonts
evolved from Eocene armadillos. - Molecular Ecology. 25 (14):
3499–3508. - K. J. Mitchell, A. Scanferla, E. Soibelzon, R. Bonini, J.
Ochoa & A. Cooper - 2016.
- The phylogenetic affinities of the extinct glyptodonts. - Current
Biology. 26 (4): R155–R156. - F. Delsuc, G. C. Gibb, M. Kuch, G.
Billet, L. Hautier, J. Southon, J.-M. Rouillard, J. C. Fernicola, S. F.
Vizca�no, R. D. E. MacPhee & H. N. Poinar - 2016.