Cedrelospermum nervosum

Overview

Cedrelospermum nervosum is an Eocene tree preserved with leaves and winged fruits attached to branches. It is studied as an extinct relative in the elm family. Connected organs, rather than isolated fragments, reveal the ancient plant.^[1][2]

Key facts

Why is a branch with attached leaves and fruits special? It directly connects organs that might look like different plants if found separately. A small zigzag twig became a clue to one tree’s identity.^[1][2]

Time and place

This North American plant lived in the Eocene, around 50 million years ago. Material from the Green River Formation in present-day Utah and Colorado, USA, has been studied. Ancient lake sediments preserved delicate relationships between twigs and leaves.^[1]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

Leaves range from narrowly elliptical to egg-shaped and lance-shaped. Fruits typically have a large main wing and a small secondary wing. Exceptions with only one wing add interest to comparisons among fossils.^[1]

A study examining 81 leaves of Cedrelospermum nervosum found lengths of approximately 1.1–6.5 cm, averaging 3.4 cm. Branches bearing small leaves and winged fruits were preserved together, helping reconstruct the extinct tree.^[7]

Habitat and reproduction

Small winged fruits are associated with wind dispersal. Researchers proposed that the genus may have been an early colonizer of open spaces. This interpretation explored its life by reading numerous fruits alongside evidence from lake sediments.^[1]

Fossil discovery

Manchester’s 1989 study compared branches bearing flowers, leaves, and fruits in detail. Plant organs once separated under different names came together in one form. Museum specimens and records demonstrate these connections.^[1][2]

References

1. Manchester1989 — Leaves and reproductive organs of Cedrelospermum attached to branches
2. Florida Museum — A Cedrelospermum branch with attached leaves and winged fruits
3. Jepsen (1966) — Description of Icaronycteris index
4. 2023 study — Comparing early bat skeletons
5. Manchester1989 — Leaves and reproductive organs of Cedrelospermum attached to branches
6. Florida Museum — A Cedrelospermum branch with attached leaves and winged fruits
7. Manchester (1989) — Cedrelospermum with leaves and fruits preserved together

Research questions

Do leaves and fruits reveal close relatives in the same way? Comparisons of several parts can reveal relationships invisible in one organ alone. Connected branch fossils raise questions about both plant classification and wind dispersal.^[1]

Observation

Follow a zigzag twig to the points where leaves and winged fruits attach. Comparing the large and small wings makes the unusual form of each tiny fruit clearer.^[1]