1) Gymnosperms first arose 350 million years ago in the Devonian period and flourished during the Carboniferous and Mesozoic eras. They produce naked seeds that are fertilized directly without ovaries or fruit. 2) Early gymnosperms like Cycadofilicals resembled ferns but had primitive seeds. Cycadales first appeared in the Triassic period and still exist today, making them extremely ancient. Bennettiteles flourished in the Triassic to lower Cretaceous. 3) Coniferales have a geological history dating to the lower Carboniferous around 300 million years ago but were most prominent before Cordaitales went extinct in the Permian period. Texales also

1. Geological Rise And Fall of
Gymnosperm
Presented by……
Patel Hasti G.
Botany CBO-402
M.Sc. Sem – 1
Department of Life Science,
H.N.G.U. Patan

2. Content
Introduction
Geological history of Gymnosperms
Geological Rise and Fall of different classes
are Gymnosperm

3. Introduction
• Gymnosperms are a group of plants which produce
seeds that are not contained within an overy or
fruit.
• The seeds are open to the air and are directly
fertilized by pollination.
• “ Gymnosperm’’ word come from the Greek word
“naked seed”.
• In Greek ‘Gymno’ means ‘naked’ and ‘sperm’
means ‘seed’.

4. Cont…
• Gymnosperms develop their seeds on the surface
of scales and leaves, which often grow to from
cone or stalk shapes, contrasting in characteristics
from the Angiosperms flowering plants which
enclose their seeds within an overy.
• Gymnosperms are therefore regarded as
intermediate between pteridophyta and
Angiosperms.

6. Geological History of Gymnosperm
• Geological history reveals that the gymnospers are
the most ancient seed plants that arose during
upper devonian and lower carboniferous in the
palaeozoic era (350 million year ago ) but
flourished well during mesozoic era.
• These appeared during carboniferous and are
evidence of the origin of gymnosperms from an
ancient stock of fern like plant.

7. Geological rise and fall of different
classes of Gymnosperms
• These appeared during Carbonifarous and are an
evidence of the origin of Gymnosperms from an
ancient stock of fern like plant
• They had fern like general appearences and foliage
but had the primitive types of seed.
• These resembled so much with ferns that the
period during with they flourished is often called
“age of ferns.”

8. 1] Cycadofilicals :-
• These plants appeared first
in upper Devonian and
flourished in carboniferous
and become extinct in jurasic
period of mesozoic plant of
this group resemble to the
filicales in shape of their
layer.
• Usually pinnate leaves and in
the venation of leaflets.

9. 2] Cycadales :-
• The group is consists
of nine genera and
more then a hundred
species.
• They appeared first in
upper triassic timer
and are present even
today.
• This indicate that this
group is extremely
ancient.

10. 3] Bennettiteles :
• This group of fossil
plants flourished well
during the triassic to
lower cetaceous
period of mesozoic
era.
• As the carboniferous
has been called as
‘age of ferns’.

11. 4] Ginkgoales :-
• At present this order is
represent by only one
living genera is ginkgo
biloba.
• During the trissic of
mesozoic age i.e. about 20
corers years ago.

12. 5] Cordaitales :-
 This is a group of paleozoic
woody tree like gymnosperms.
 This group began to decline in
carboniferous and were
completely extint by end of
permium.
 As per records the Cordaitales
occurred side by side with
cycadofilicales.

13. 6] Coniferales :-
 Geologically its history does
not go back beyond the
jurassic period.
 It has been recorded in the
lower carboniferos i.e.
almost 300 million year ago.
 Before the cordaitales
become extinct they were in
existence by the upper
permian.

14. 7] Texales :-
• This order is of great historical
interest for, where as today it
shows only a scantly
distribution at one time its
members played an important
role in the forest of the
northern hemispheres fossile
records extending back to the
cretaceous.

15. 8] Gnetales :-
• Forster and Gifford
described Gnetales as “a
small group of
Gymnosperm like plant.”
• Gnetales have no fossil
plant.

16. References
 Botany for Degree Student –Gymnosperms
By Vasishta P C
 A Text Book of Botany
By Pandey S N , Misra S P and
Trivedi P S