ammoglyph

American  

[am-oh-glif, am-uh-] / ˈæm oʊˌglɪf, ˈæm ə- /

noun

1. a pattern or design originally created in sand by early humans and now fossilized.

   The triangular shape etched into the sand-turned-rock is believed to be an ammoglyph.

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Etymology

Origin of ammoglyph

Coined in 2019 by Canadian geologist Charles William Helm and colleagues; Greek ámmo(s) “sand” + glyph ( def. ); cf. ammophilous ( def. )