lpetrich
Contributor
Is This What The Ancestor Of All Flowers Looked Like? | IFLScience noting The ancestral flower of angiosperms and its early diversification | Nature Communications
The authors mapped plants' flower features onto those plants' phylogeny, and deduced from there which ancestral plants likely first had flower-feature versions.
The original flowers were bisexual, with both stamens (male) and carpels (female: pistil parts) in each flower, with the stamens surrounding the carpels. They had no distinction between petals and sepals, and they looked something like a water-lily flower.
The authors concede that they do not have any fossils to compare to, and that goes to show what a mystery the early evolution of angiosperms is. From the fossil record, the angiosperms started becoming common only 140 million years ago, in the early Cretaceous. But what became common then was mostly eudicots, and eudicots' characteristic "tricolpate" pollen first appeared then. So it's usually inferred that eudicots originated about then.
The trouble here is that there are many non-eudicot angiosperms: monocots, magnoliids, and the ANA clades (ANA includes water lilies). So they would have to have diverged earlier, during the early angiosperm "dark age".
There is some recently discovered evidence, however: New fossils push the origin of flowering plants back by 100 million years to the early Triassic -- ScienceDaily noting Frontiers | Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland) | Plant Science But that evidence is pollen grains -- pollen and spores can survive when the rest of the plant or fungus doesn't.
The closest relatives of angiosperms are gymnosperms (naked seeds as opposed to covered seeds). There are four extant (present-day) groups of them: conifers, cycads, Gnetales (Gnetum, Ephedra, Welwitschia), and the ginkgo (
Gymnosperm, Pinophyta: the conifers), and they all diverged around 300 million years ago, at the Carboniferous-Permian boundary. The first seed plants likely lived in the late Devonian, around 370 million years ago.
It is not very clear which of these groups the angiosperms are closest to -- if any. So the mystery continues.
The authors mapped plants' flower features onto those plants' phylogeny, and deduced from there which ancestral plants likely first had flower-feature versions.
The original flowers were bisexual, with both stamens (male) and carpels (female: pistil parts) in each flower, with the stamens surrounding the carpels. They had no distinction between petals and sepals, and they looked something like a water-lily flower.
The authors concede that they do not have any fossils to compare to, and that goes to show what a mystery the early evolution of angiosperms is. From the fossil record, the angiosperms started becoming common only 140 million years ago, in the early Cretaceous. But what became common then was mostly eudicots, and eudicots' characteristic "tricolpate" pollen first appeared then. So it's usually inferred that eudicots originated about then.
The trouble here is that there are many non-eudicot angiosperms: monocots, magnoliids, and the ANA clades (ANA includes water lilies). So they would have to have diverged earlier, during the early angiosperm "dark age".
There is some recently discovered evidence, however: New fossils push the origin of flowering plants back by 100 million years to the early Triassic -- ScienceDaily noting Frontiers | Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland) | Plant Science But that evidence is pollen grains -- pollen and spores can survive when the rest of the plant or fungus doesn't.
The closest relatives of angiosperms are gymnosperms (naked seeds as opposed to covered seeds). There are four extant (present-day) groups of them: conifers, cycads, Gnetales (Gnetum, Ephedra, Welwitschia), and the ginkgo (
Gymnosperm, Pinophyta: the conifers), and they all diverged around 300 million years ago, at the Carboniferous-Permian boundary. The first seed plants likely lived in the late Devonian, around 370 million years ago.It is not very clear which of these groups the angiosperms are closest to -- if any. So the mystery continues.
