Admiring Horsetails

By | May 5th, 2022|Adobe CS5, Dinosaur Fans, Main Page, Photos, Photos/Pictures of Fossils|0 Comments

Horsetails (sphenopsids) continue to thrive although their Carboniferous heyday is long behind them. Once a much more extensive group, these vascular plants, believed by many palaeobotanists to be closely related to ancestral ferns, are now represented by about twenty species, all contained in the genus Equisetum.

Horsetails
Horsetails (Equisetum) continue to thrive as they are able to grow in areas where other plants would find it difficult to get a foothold. Often regarded as weeds, these tough little plants are essentially living fossils, as the earliest examples of the genus Equisetum date from the Early Jurassic of South America.

A Living Fossil

When team members at Everything Dinosaur see a clump of horsetails, often growing on waste ground we stop to admire them. These tough little plants deserve respect. After all, they are essentially a living fossil, the oldest fossil remains of modern horsetails (genus Equisetum), date from approximately 190 to 182 million years ago (early Pliensbachian to early Toarcian), represented by Equisetum dimorphum from the Early Jurassic of South America (Chubut Province, Argentina).

Horsetail fossils - Equisetum dimorphum.
Photographs of Equisetum dimorphum sp. nov. from the Lower Jurassic of Chubut Province, Argentina. 1-2. Part and counterpart of a strobilus showing the hexagonal sporangiophores and the long leaves of MPEF-Pb 5894a and MPEF-Pb 5894b; 3. Detailed inner view of 1 showing oblong sporangia of MPEF-Pb 5894a; 4. Isolated external cast of sporangiophore showing central umbo of MPEF-Pb 6477a. Abbreviations: le, leaves; s, sporangia. Scale bars 1-2 = 3mm; 3 = 1 mm; 4 = 0.5 mm. Picture credit: Elgorriaga et al.