BIAWAK - International Varanid Interest Group

BIAWAK VOL. 4 NO. 4
124
Fig. 1. The evolution and dispersal route of varanid lizards. Laurasian hypothesis is based on fossil records (Estes,
1983) and indicated by grey arrows, whereas Gondwanan hypothesis is based on species diversity (Hutchinson &
Donellan,
Figure 1. The1993) evolution
and
andindicated dispersal route
by
of
white
varanid
arrows.
lizards. Laurasian
Map shows
hypothesis
Late
isCretaceous-Tertiary based on fossil records (Estes,
transition
1983) and
(∼65
indicated
Ma),
inredrawn
grey
after arrows, a whereas paleogeographic Gondwanan hypothesis map available is based on at species http://jan.ucc.nau.edu/~rcb7/globaltext2.html diversity (Hutchinson & Donellan, 1993) and indicated in by white Ron arrows. Blakey, Map shows Geology
Department, Late Cretaceous-Tertiary Northern transition Arizona (∼65University. Ma), redrawn after Laurasian a paleogeographic and Gondwanan map availablefragments at http://jan.ucc.nau.edu/~rcb7/globaltext2.html are indicated in this map with by the
Ron Blakey, at Geology Department, Northern Arizona University. Laurasian and Gondwanan fragments are indicated in this map with the letter
letters “L” and “G”, respectively.
„L“ and „G“, respectively.
L
L
L
G
G
X
G
G
G
G
G
G
Fig. 2. Hypothetical dispersal of ancestral varanids from Asia as illustrated in Estes (1983). Varanid lizards are
thought to have originated in central Asia during the Cretaceous (~80 Ma) based on fossils found in Mongolia,
whereas the genus Varanus is thought to have emerged in Africa sometime in the Eocene, more than 37 Ma (Holmes,
2010).
Received: 16 April 2010; Accepted 4 November 2010