Coastal Fossil Survey (Lavernock Point)

I surveyed the coastline at Lavernock Point, Wales, across three field visits (Jan, March, and April 2026), documenting fossils in-situ and mapping them against local bedrock formations.

My goal:

The aim of this project was to survey and document fossils along the coastline at Lavernock Point, mapping each find to its corresponding bedrock formation using the BGS Geology of Britain viewer. My objectives were to identify and photograph fossils in-situ across multiple field visits, record GPS locations for each find, and cross reference findings with existing geological literature to contribute to local records. Moreover, I wanted to contribute to the local records by cross referencing written literature information and my fossil findings. My other goal for this project was to inform citizens of Penarth and more about the ancestry of their surroundings.

Method:

• Photographed each fossil where I found it

• Logged GPS location on my phone

• Matched each find-spot to its bedrock formation using the BGS Geology of Britain viewer

What I found:

6 fossils documented across the three trips, under varying tide conditions (low, high with surging currents, afternoon low)

Analysis:

The fossils I collected across three trips tell a consistent story that matches what's already published about this stretch of coastline. Fossils 2, 3, and 5 all point to the same environment described in the literature for the Blue Lias: a warm, shallow sea that was regularly flooded with mud and clay washing in from the land. The alternating bands of limestone and shale around fossils 2 and 3 (driven by long-term shifts in Earth's orbit known as Milankovitch cycles) match the rhythmic layering geologists have documented here before. Fossil 5, a colonial coral, adds physical evidence for this too as its clustered growth form is exactly what you'd expect from a coral struggling to survive in murky, sediment choked water.

Fossils 4, 5, and 6 go further, together reconstructing the story of "reef recovery" after the End-Triassic mass extinction. Fossil 5's stunted coral growth shows reefs hadn't yet bounced back. Fossil 4, an ammonite, shows the opposite trend as increasingly complex shell suture patterns as ammonites rapidly evolved in the wake of the extinction. Fossil 6, a giant file clam, shows a third, independent line of evidence: a species that survived the crisis and then grew unusually large once competition had been wiped out. Bringing these three unrelated fossil types together (coral ecology, ammonite evolution, and bivalve growth patterns) to point toward the same event felt like the most rewarding part of the project; it meant connecting ideas across different areas of biology and geology rather than treating each fossil in isolation.

Finally, fossil 1 and the preservation of fossil 4 both match the well-documented chemistry of the Lower Lias mudstones here, showing that even the way these fossils were preserved lines up with what's already known about the area.

Conclusion:

Across depositional environment, evolutionary patterns, and preservation chemistry, all six fossils independently point to the same paleoenvironmental picture that's already been published for the Blue Lias at Lavernock Point, supporting my original hypothesis. That said, I want to be upfront that this should be read as provisional rather than conclusive. Because I chose not to physically extract any fossils to prioritize minimal disturbance to the site over lab grade certainty. My identifications rest on visual and photographic comparison rather than laboratory confirmation. That was a deliberate trade-off: it protected the site for future visitors and researchers, but it also means there's a layer of uncertainty in my conclusions that I think is worth being honest about.

Here are the pictures of the fossils: (The red number on them signifies their number in the study)

Challenges:

Access to the shore was tide restricted, GPS precision was limited and I wasn't sble to extract fossils for lab identification, so the identification relied on in-situ photos and bedrock context alone.