Progymnosperms: Seed plant ancestors

1
Progymnosperms Seed plant ancestors?
Archaeopteris
Aneurophyton From ca. 365 mya
2
Earliest fossil seed (385 mya)Runcaria
3
Seed plants 5 phyla

• Cycadophyta
• Ginkgophyta
• Coniferophyta Gymnosperms
• Gnetophyta
• Anthophyta ( Angiosperms)

4
GymnospermsFour extant phyla
5
Cycadophyta140 species
6
Cycads in South African park
7
Cycads are dioecious this female plant has
ovulate scales
Large ovules formed before fertilization
8
Cycad male cones
Still with swimming spermbut in an indoor pool
9
Cycad leafleaflets unfurling like fern fronds
(circinate vernation)
10
Cycads as coevolutionary partners
Good for insects, maybe bats, but not so good for
humans
11
Ginkgophyta1 surviving species
12
Ginkgo biloba
What unusual feature (for gymnosperms) makes
Ginkgo such a good city tree?
13
Swimming sperm
From Cycad From
Ginkgo
14
Coniferophytaabout 550 species
15
Pinus longaeva (bristlecone pine), like all
pines, is monoecious, with separate female and
male cones
female
male
16
Pine ovule

17
Another conifer Taxus brevifolia (Pacific yew)
18
Gnetophyta3 genera
19
Gnetum a gymnosperm with vessels in its xylem
20
Welwitschia mirabilis
Female cones
Male cones
21
Ephedra
22
Amborella trichopoda sister taxon to the
angiosperms ( ancestral flowering plant)
Is the success of angiosperms due to evolution of
the flower?
23
(No Transcript)