Episode 4: The fossil forests of Gilboa

A few days after the interview in the Royal Ontario Museum with Dave Rudkin on Isotelus rex, the Palaeocast team headed south to the New York State Museum (NYSM), Albany, USA. Here we got a chance to visit one of the world’s most important palaeobotanical collections and were talked through the history and significance of the fossils at Gilboa by Professor William Stein of Binghamton University, who had recently published a paper on the forests in Nature.

Podcast: Download (Duration: 49:37 — 68.2MB)

Located in Schoharie County, New York, USA, the town of Gilboa was formed in 1848

The picturesque town was nestled on the banks of the Schoharie River

In 1869 a large flood, termed a ‘freshet’ scoured the river banks and exposed rocks, leading to the discovery of the first fossils

To meet the ever increasing water demands of New York the Schoharie River was dammed to formed what is now the Schoharie Reservoir. In 1924 the town was demolished and submerged

To provide raw materials for the dam, the rocks along the riverbank were quarried. This uncovered many more fossils which were collected by the NYSM

The substantial tree stumps were found in large numbers and were notably still upright

The rooting horizon is a dark grey sandy mudstone clearly belonging to a
wetland coastal plain environment. This is overlain by large beds of fine sandstone dated at approximately 400 million years old

There were a few “paleontological difficulties” when one of the trucks was too heavily laden with fossils and collapsed the bridge over Breakabeen Creek

The fossils had always attracted a lot of interest, but it was Winifred Goldring who’s work really stood out

Display of the Earth’s ‘oldest forest’ at NYSM

In 2010 Prof. Stein’s team got the opportunity the re-exhume the fossil bearing rocks alongside the Schoharie River

with a little help from the water board

Over a square Kilometer was re-exposed

And 30 additional fossils were recovered during the process

The re-exposed site possessed approximately 200 holes where tree trunks once used to stand

This enabled the researchers to map out the ancient forest as it once stood

A good analogy for the ecology and structure of this forest would be the palm forests of Mexico

The Eospermatopterus trees, like the palms have a frondose crown

…and a long trunk

Palm tree roots have a fibrous, non-woody, light-weight construction with a narrow mantle of hollow roots and continuous root initiation, providing accommodation for increasing height

Eospermatopterus roots appear remarkably similar

A surprise was a horizontally growing tree that ‘crept’ along the forest floor, with roots along the length of its trunk

The roots on the aneurophytaleans did not cover the entire length of the trunk, suggesting that these trees were ‘ascenders’, climbing up other trees. They even showed ‘avoidance’ behavior, growing around other trees whilst on the forest floor

Reconstruction of the ancient forest by Anna Kotler

Images courtesy of Prof. Stein

The following video was taken by Dr. Chris Berry of Cardiff University who was part of the 2010 research team. His video shows details of how the forest floor was exposed and the methods of how they went around mapping such a large area.