At a maximum size of about 20 cm Horneophyton was one of the commonest early land plants found in the Rhynie Chirt (a area of rock in Scotland with exquisitely preserved fossils from the early Devonian about 400+ million years ago).
Interestingly it showed an affinity to both bryophytes (mosses and liverworts) and the earliest vascular plants. It is considered a missing link by many paleobotanists.
They are the simplest known spore bearing plants and had neither true vascular tissue, true roots or leaves. Horneophyton may have led to the evolution of the modern plants known as Hornworts (Anthocerotophyta).
Glossopteris is a fossil plant which helped to change the way we understand the Earth.
When the first fossils of Glossopteris were found in the Nineteenth Century, it was assumed to be a fern (its name means ‘tongue-fern’, given for its long, tongue-shaped leaves). Further finds revealed that it was actually a seed plant with pollen-bearing organs, and that it grew as a small tree with a woody trunk.
Leaves of Glossopteris have been found in rocks of Permian age (roughly 300 to 250 million years ago) in India, Australia, South Africa, South America, Africa and Antarctica. Their distribution, and that of other fossil species, was one of the lines of evidence which were gathered by Alfred Wegener, to support his theory of ‘continental drift’, the pre-cursor to modern plate tectonics. Wegener argued that that the continents of the Southern Hemisphere had once been joined together (in a continent known as Gondwana), and had drifted apart. Wegener’s ideas were not widely accepted when proposed in the 1910s and it was not until five decades later that the idea of drifting continents became mainstream.
G is for…. Was written by guest blogger paleobotanist and Science communicator Susannah Lydon.
If you would like to produce a paleobotanical blog for fossilplants.co.uk please contact me at firstname.lastname@example.org or @fossilplants on Twitter.
Well it had to be really!
Ferns (and with that I mean Pteridophytes) have been around since the mid Devonian although most modern fern families have only been here since the early Cretaceous.
When we think of ferns we think of just one class of Pteridophytes (the Leptosporangiate ferns) but quillworts, equisetums and whisk ferns are also members of this group. There are over 12,000 species. The oldest known extant genera of leptosporangiate ferns are Marattia, Angiopteris and the Osmundas. They have evolved to grow in every different environment from desert to totally aquatic and are often the first colonists on disturbed ground.
We grow over 80 different species of fern in the fossil garden including quillworts, equisetums and the aquatic Marsilea.
Hailing from as far back as the Carboniferous (360-299 million years ago) these fern relatives once grew to 10meters tall (in the case of Calamites). The modern day Equisetales (in the genus Equisetum) don’t grow anywhere near as big with the tallest, Equisetum giganteum, growing to a mere 3 meters tall.
The trunks of Calamites (as with modern horsetail, Equisetum) grew from a underground rhizome and were filled with air. When a Calamites toppled, the trunk would fill with sediment forming a cast fossil. It is these fossils that are most often found.
Equisetales are represented in the fossil garden by equisetum arvense, E. fluviatile, E. giganteum, E. scirpoides, E. hymale and E. camtschatcense.
An extinct family of seed ferns (a group of plants somewhere between a fern and a cycad) that existed during the Triassic (about 200 million years ago).
Dicroidium are also known as fork leaved seed fern due to the fern like fronds having a obvious fork. Male and female plants were believed initially to be separate species.
They inhabited what was at the time the supercontinent Gondwana.
A group of about 70 plants both extant (surviving to this day) and extinct. They have a microfossil (very small fossils, in this case pollen) record dating back to the Hauterivian period of the lower Cretaceous (about 130 million years ago). Scientists have found it difficult to place them in a family with any of the other flowering plants and believe them to be a sister group to some of the earliest evolving flowering plants. We have 2 species in the fossil garden Chloranthus japonica and C. Oldhamii.
A group of Cycad like plants that existed from around 250 million years ago until the uppermost cretaceous (about 70 million years ago).
Scientists believe they may be a sister group to the Angiosperms (flowering plants) instead of being gymnosperms (non flowering) like the Cycads they resemble.
So after recently having had a very short conversation on Twitter about a dinosaur alphabet I have decided to to produce a alphabet of ancient plants. Some will be plants that are extinct, some plants that are still around today, some I have probably even got growing in my garden.
So here is the first letter…
A is for……
A group of 3 aquatic angiosperm (flowering plant) species known from fossils dating to about 125 million years old. It’s now extinct but paleobotanists believe, because of the way its flowers were laid out, it represents a new basal (early) group of flowering plants.