Biodiversity is increasing in the oceans and on land.

Pecopteris

Pecopteris species had fern-like leaves and belonged to an extinct group of plants called Medullosales.

They were common during the Carboniferous in the coal swamps of present-day Europe and North America.

Calamites

This is a fossil of a large horsetail plant that could be up to 20 metres high.

The stems of all horsetails are divided into segments, and nearly all are hollow. When such a plant dies, the hollow stem is often filled with mud which then hardens and becomes a fossil, as in this example.

Sphenophyllum

Sphenophyllum was a small and delicate horsetail. It grew amongst the ground vegetation in dense clusters of plants that supported each other.

Dipnoi

One of these fossils is of a scale from a lungfish, and the other is of the impression made by the scale in sediment. Limestone separated out from bottom sediments and, over time, formed a ball around the scale that was harder than the surrounding rock. The fossilized scale was protected and it was easy to find the limestone ball when the surrounding rock eroded.

The first lungfish lived in salt water, but the species that existed during the Carboniferous and since have lived in fresh water.

Rhizodus hibberti

This is a fang from Rhizodus. Its front fangs could be 22 centimetres long, and the entire fish could be up to seven metres long, the largest freshwater fish known ever to exist.

Rhizodus lived in lakes, rivers and swamps of what are now Europe and North America. It hunted large sharks, lungfish, amphibians and other sarcopterygian fish.

Trigonocarpus

These are seeds that have been named Trigonocarpus. They are from a plant that belonged to an extinct group of plants called Medullosales.

Cordaites

This is the leaf of a tree that grew to a height of 20–30 metres and was related to conifers. Some Cordaites species grew in freshwater swamps, in somewhat the same manner as the saltwater mangroves of today.

Ovopteris decheni

Ovopteris was one of several types of plant that had large fern-like leaves. It belonged to an extinct group of plants called Medullosales. Even though such plants looked like ferns, their fossilized leaves have been found with seeds attached, instead of spores. Scientists therefore consider them to be seed plants rather than ferns.

Spirifer

Spirifer lampshells were common in what are now Europe and North America during the Carboniferous. They sat firmly on the ocean floor and filtered food from the water with a spiral-shaped arm that was covered with small tentacles.

The shell’s butterfly-like form created natural currents which, merely by opening the shell a little bit, channelled water with plankton to the capturing organ inside.

Spirifer

Spirifer lampshells were common in what are now Europe and North America during the Carboniferous. They sat firmly on the ocean floor and filtered food from the water with a spiral-shaped arm that was covered with small tentacles.

The shell’s butterfly-like form created natural currents which, merely by opening the shell a little bit, channelled water with plankton to the capturing organ inside.

Onychocrinus, Platycrinites and Phillipsia

Displayed here are two species of sea lily and one trilobite that lived in shallow water near a river delta. The sea lilies specialized in different kinds of food and could live side by side without competing with each other.

Phillipsia belongs to the only group of trilobites which survived the transition from the Devonian to the Carboniferous. They lived in tropical oceans, and not many fossils of them have been found. All that can be seen here is the animal’s tail shield, possibly discarded when it shed its shell.

Archimedes

Moss animals are microscopic animals that form large colonies with hundred of individuals. Archimedes is a fossil of such a colony, but only the central part of it. Each individual had a little chamber that hid most of its body. It fed on plankton caught with its microscopic tentacles.

Bellerophon

Bellerophon had a symetrically coiled shell. In the middle of the shell was a ridge with a long narrow opening through which the animal breathed. Such shells were common during the Carboniferous and before. But there is nothing like them today, because this type of shell is easy to break open. Evolution has therefore led to the development of snails with shells that provide better protection.

Euomphalus

Euomphalus species probably fed primarily by scraping algae from rocks and other hard surfaces. Most species had a fairly broad, flat shell that was not very strong, which may indicate that there were few predators during the Carboniferous which could effectively break open the shells of snails. Sphenophyllum was a small and delicate horsetail. It grew amongst the ground vegetation in dense clusters of plants that supported each other. Many different species of Euomphalus are known.

Baylea

Baylea was a snail that fed on algae and sludge on the ocean floor. It belonged to a group of snails whose shells already during the Carboniferous resembled those of modern snails.

Relatives of Baylea are the most common snails today.

Serpulospira

The snail Serpulospira had a spiral-shaped shell whose whorls did not touch each other. With such a shell it was difficult for the animal to move, and it probably remained stationary on the ocean floor. Such shell forms are not common among snails today, probably because they make the shell weak, and therefore easy for efficient modern predators to break apart.

Posidonia beckeri

The mussel Posidoniabeckeri lived in what are now Europe, North America and China during the Carboniferous.

Posidonia are usually found in places where the ocean waters were deep and the bottom was free of oxygen. This suggests to scientists that Posidonia may not have lived on the ocean floor like other mussels, but was instead attached to algae or other floating objects.