Marrolithus is an extinct genus of trinucleid trilobite that lived during the Ordovician period.[1]

Marrolithus
Temporal range: Ordovician
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Clade: Artiopoda
Class: Trilobita
Order: Asaphida
Family: Trinucleidae
Genus: Marrolithus
Bancroft, 1929
Species

Marrolithus bureaui Oehlert, 1895

Marrolithus orthogonius Dean, 1967

Palaeobiology

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Ontogeny

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During the meraspid period of ontogeny, the glabella of Marrolithus bureaui became compressed. During this ontogenetic stage, the species also developed a pronounced sub-quadrangular cephalic outline. The alae disappeared later on in development.[2]

References

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  1. "Marrolithus". Paleobiology Database. Retrieved 11 June 2026.
  2. Delabroye, Aurelien; Cronier, Catherine (July 2008). "Ontogeny of an Ordovician Trinucleid (Trilobita) from Armorica, France: A Morphometric Approach". Journal of Paleontology. 82 (4): 800–810. doi:10.1666/07-084.1. ISSN 0022-3360. Retrieved 11 June 2026 via Cambridge Core.