> ## Content Index
> Fetch the complete content index at: https://theparnassian.com/en/llms.txt
> Use this file to discover other available public pages before exploring further.

# 350-million-year-old fossils in the stone steps of a stairwell
- URL: https://theparnassian.com/en/sluchaino-zametil-okamenelosti-vozrastom-350-millionov-let-na-stupenkakh-v-podezde/
- Published: 2026-10-26T11:53:50.000Z
- Updated: 2026-10-26T12:30:08.000Z
- Author: Alexandr Radayev
- Tags: Observations, Science, Palaeontology, Nature

I happened to notice 350-million-year-old fossils on the steps in a stairwell.

The white rings, semicircles and ovals that might be mistaken for ammonites are in fact fragments of crinoid stems, cross-sections of solitary corals and brachiopod shells.

The stone from which the steps were cut was formed on the floor of a warm, shallow sea, where for millions of years the remains of marine animals accumulated, bound together by calcareous mud.

![](https://theparnassian.com/content/images/2026/10/file_405.jpg)

![](https://theparnassian.com/content/images/2026/10/file_406.jpg)

![](https://theparnassian.com/content/images/2026/10/file_407.jpg)