Biology Reference
In-Depth Information
Figure 7.3
Physiography of Hispaniola (Haiti and the Dominican Republic, Greater Antilles),
showing location of the Artibonite fl ora. Map created by Trisha Distler, Missouri Botanical
Garden, St. Louis, based on the U.S. Geological Survey's Shuttle Radiography Topography
Mission (SRTM) 90m DEM digital elevation database.
Formation of adjacent Puerto Rico were more tropical, comparable to those
growing presently under a MAT of about 28°C, the general trend seems
roughly in accord with cooling in the Neogene, muted by the insular envi-
ronment of the Antilles.
In Central America, fossil fl oras are also mostly scattered geographically
and stratigraphically. The Padre Miguel and the Herrería fl oras of eastern
Guatemala are similar in age, with the Padre Miguel probably being slightly
older (late Miocene to Mio-Pliocene). The Padre Miguel is an upland fl ora
with pollen of
Picea
and other cool-temperate plants from the north (
Jug-
lans
,
Ulmus
). The Herrería fl ora is from the lowlands, as indicated by the
marine dinofl agellate
Operculodinium
, as well as by
Rhizophora
pollen that
reaches nearly 100 percent in one sample. The MAT for the more highly
elevated Padre Miguel assemblage is estimated at 2°C-3°C cooler than at
present, while the MAT of the early Pliocene coastal Herrería fl ora is esti-
mated to be 2°C-3°C warmer (Graham 1998). These are approximations,
but they are consistent with the cooling trend, altitudinal difference, and
the absence of appreciable upwelling that characterized the later middle
Pliocene Paraje Solo fl ora of southeastern Mexico.
An exception to the scattered nature of northern Latin America fossil
fl oras is a series from the late Eocene, early to middle Miocene, late Mio-
cene, and Quaternary in the canal region of Panama. Samples from the
Tertiary sediments were collected from roadside and canalside exposures,
