The silver messenger. (Challis, Idaho) 1890-1912, 1898-02-08

THE MESOZOIC ERA-AGE OF
REPTILES.

CycauS In plants.
The Mesozoic is divided into
three divisions-the Jurasic,
Triasic and Cretaceous. The first
the Jurasic, lies unconformably
on the Permain, or coal measur-
es. The break in the life system
are greatest here. The fossils
of Jurasic are very different to
those of the coal measures.
The most striking thing we
find is the sweeping change in
life forms. All our old friends
the corals are gone, and new
kinds appear. ALL the orthoce-
rites-the square shouldered
Braciopods, all the armless GRIN
ODDS, SO plentiful in the Paleozoic
have passed away, SO to have the
Lepideodendrids, Sigillirids and
Calimites, they are replaced by
other, and very different forms.
Conifers and cycads are here
with their great spread or leafy
branches, and starlike blossoms.
Many kinds of shrub, and flower,
nearly thousand kinds have
been found and classified.
Among fishes we find Ganoids
and Placoids, but the Ganoids
are more and more like the mod
ern Telosts, the teeth of the
Placoids are becoming more star
like.
Labvrinthidonts, a family of
reptiles, which we found in the
coal eliminate here and soon be-
come extinct. Many beast like
reptiles are found here, but no
birds. 1t seems strange that we
would not find representatives
of the bird family in this strata
for mammals of the marsapaul
kind come in the Triassic. LIE
Conte says: Birds are a sub
branch of the reptile branch of
the vertebrate stem, which &C.
counts for the fact-to all in
tents and purposes" Crinoids
beautiful, plumosed armed and
lily-like, free asteroids, echinoids
are abundant, bivalves are also
plentiful. The ammonite family.
introduced the Devonian, as
Goniatites are here as leratites.
They continue through the
Triassic and Cretaceous then
pass away forever.
TRIASSIC.
Reptiles are the rulers of this
Age, and we will devote all our
space to them, outside of saying
that the plant family is very
little changed from that in Jura.
The reptiles were the lords of
Creation at this period-rulers
of the sea in place of sharks and
whales-rulers on land in place
of beasts-rulers in the air in
place of birds.
Marine Sauaians-The 1cthy-
osaurus, was a huge monster,
with thick body, short neck,
eyes IL to Is inches in diameter,
and jaws set with hundreds of
strong conical teeth, the limbs
were paddles suitable for swim
ming, or when used like a seal
uses his clippers for locomo-
ton on land.
The bones of the vertabrea are
biconcave like those of the fish.
The perfect skeletons of these
reptiles have been found with
even the impressions of the in
testines plainly visible, and the
contents of it's stomachs reveal
ing the nature of it last meal,
have been found, preserved in
the chalks and sandstone.
Plesiosaurus-Lizzard- like, was
a long, slender reptile, with a
very long neck, small head, with
clipper happers" for legs, and
fish-like bones" There were
various kinds of minor reptiles
OF the ocean, but we have not
space to describe them all.
Land Saurious-These were
the higher grade Many of them
had long, powerful hind legs,
large hipbones, very short fore
legs. This characteristic shows
that they walked on land, and
mainly on their hind legs, like
kangaroo. Some had three toes
on their feet, some had four, and
others had five or six.
The most interesting are the
lguandon and the Megalosaurus.
The former, Judging from it's
bones, was two or three times
larger than an elephant, vet a
skeleton found in South Carolina
shows plainly that it walked on
its hind legs, something after
the fashion of a duck. 1t was
herbiverous and it's jaws were
beaked in front, its teeth were
set with a slope or incline, and
IFS food was ground by the re- |
Deated DaSSinp and ra pacc;,oor ~f