Question

What groups of terrestrial plants that existed in late Paleozoic time survive today?

Short answer

The major groups of terrestrial plants that originated in the late Paleozoic era and still survive today are Seed Ferns (Pteridosperms), Horsetails (Sphenopsids), Clubmosses (Lycopsids), Ferns (Pteridophyta), and Gymnosperms. These ancient plants can be traced back millions of years and have evolved and adapted in various ways to continue to exist today. Examples of these plants include Glossopteris and Neuropteris (seed ferns), Equisetum (horsetails), Lycopodium (clubmosses), various fern families, and conifers, cycads, ginkgos, and gnetophytes (gymnosperms).

Step-by-step solution

Brief Introduction to Late Paleozoic

The late Paleozoic era was a period in Earth's history lasting from about 323 million years ago to 252 million years ago. The late Paleozoic comprises two geologic periods: the Carboniferous period (359-299 million years ago) and the Permian period (299-252 million years ago). It was a time of significant geological and climatic changes, such as the assembly of the supercontinent Pangea, glaciations, and significant changes in the climate. During this era, various groups of plant species evolved, some of which continue to exist today.

Surviving Plant Groups from Late Paleozoic

Some of the major groups of terrestrial plants that originated in the late Paleozoic era and still survive today are: 1. Seed Ferns (Pteridosperms): Seed ferns are ancient vascular plants that reproduce by seeds. They are not true ferns, but they share some common features with modern ferns, such as frond-like leaves. Some examples of seed ferns are Glossopteris and Neuropteris. 2. Horsetails (Sphenopsids): Horsetails are vascular plants, characterized by jointed stems with "whorls" of branches emerging at regular intervals. They have a deep-rooted rhizome system that allows them to spread and colonize new areas. The most common living genus of horsetails is Equisetum. 3. Clubmosses (Lycopsids): Clubmosses are a group of vascular plants that belong to the phylum Lycopodiophyta. They have simple, needle-like leaves and reproduce by spores. Clubmosses are an ancient group, and most of the living species belong to the genus Lycopodium. 4. Ferns (Pteridophyta): Ferns are a group of vascular plants that reproduce by spores and have large, divided leaves. They are an ancient group of plants, and their lineage can be traced back to the late Paleozoic era. There are thousands of living fern species belonging to several different families. 5. Gymnosperms: Gymnosperms are a group of seed-producing plants that include conifers, cycads, ginkgos, and gnetophytes. They evolved during the late Paleozoic era and were the dominant group of plants during the Mesozoic era. Gymnosperms produce "naked seeds" that are not enclosed in a fruit, unlike angiosperms (flowering plants). These are the major groups of terrestrial plants that originated from the late Paleozoic era and still have surviving members today. Some of the plants have remained relatively unchanged for millions of years, while others have undergone considerable evolutionary changes.

Key concepts

Seed Ferns

Seed ferns, scientifically known as Pteridosperms, were significant prehistoric plants during the late Paleozoic era. Despite their name, they aren't true ferns. However, they share similar frond-like leaves with today's more modern ferns.

These ancient vascular plants distinguished themselves by reproducing through seeds instead of spores, a unique trait during their time. Notable examples of seed ferns include Glossopteris and Neuropteris. Though seed ferns are extinct today, their existence gives insight into the evolutionary transitions between non-seed and seed-bearing plants.

Many consider them a bridge in plant evolution as they had features intermediate between ferns and more advanced seed plants.

Horsetails

Horsetails, belonging to the family Sphenopsids, are some of the earliest vascular plants and have survived for millions of years. Recognizable by their tall, jointed stems, these plants are equipped with a unique system of whorls—branches that emerge at regular intervals along the stem.

A remarkable feature of horsetails is their deep-rooted rhizome system, which allows them to adapt to various environments by spreading and thriving in new areas.

• Equisetum is the most well-known living genus of horsetails today.

Horsetails have also been known for their siliceous content, making them rigid and ideal for abrasive cleaning in ancient times.

Clubmosses

Clubmosses, or Lycopsids, belong to the phylum Lycopodiophyta and are among Earth's oldest groups of vascular plants. These plants are characterized by their simple, needle-like leaves and their ability to reproduce through spores rather than seeds.

Clubmosses can often be found in woodland floors and similar cool, damp habitats, marking their resilience and adaptability. Today, most clubmoss species are grouped under the genus Lycopodium.

• They have ancient roots and offer a glimpse into early plant evolution.

Despite their name, they are not mosses but have contributed significantly to the development of the Earth's flora.

Ferns

Ferns are part of the Pteridophyta division and represent a large group of vascular plants that trace their lineage back to the late Paleozoic era. These plants are distinct due to their large, divided leaves known as fronds.

Ferns reproduce by spores, which are typically found on the undersides of their fronds. This method of reproduction makes them unique compared to seed-producing plants and has endured through millions of years of evolutionary change.

• Ferns thrive in various climates and environments due to their adaptability.
• There are thousands of fern species, each filling different ecological niches.

Their resilience and diversity have allowed ferns to persist as a vital component of modern ecosystems.

Gymnosperms

Gymnosperms are one of the most ancient groups of seed-producing plants. Unlike angiosperms (flowering plants), gymnosperms produce seeds that are not enclosed in a fruit. This trait earns them the label "naked seeds."

Evolving during the late Paleozoic era, gymnosperms became prevalent during the Mesozoic era. This group includes well-known plant types such as conifers, cycads, ginkgos, and gnetophytes.

• Conifers, such as pines and firs, are among the most widespread today.
• Gymnosperms are often adapted to cold and arid environments.

Their enduring presence highlights their adaptability and evolutionary success in diverse habitats.