Early Ordovician sea scorpions from Morocco suggest Cambrian origins and main diversification of Eurypterida

The atlas shows a 479–250 Ma reviewed eurypterid fossil-record envelope from the oldest unequivocal Fezouata material to Tetlie's reviewed latest record, not an origination or extinction interval.

Van Roy et al. document Fezouata eurypterid appendages and score morphology in a matrix, while Lamsdell et al. provide a sampled Pentecopterus comparison; these characters do not establish order-wide anatomy.

Van Roy et al. place unequivocal Fezouata sea scorpions in a sampled eurypterid morphology matrix, while Tetlie reviews historical distribution; classification remains a sampled, revisable hypothesis rather than a final order-wide tree.

Fezouata and Late Permian Russian occurrences in Van Roy et al. and Tetlie provide bounded localities across time; they do not constitute a complete geographic distribution of Eurypterida.

The cited eurypterid studies address morphology, phylogenetic placement and fossil distribution; predatory function, habitat preference, locomotor performance, body size and ecological guild remain study-limited and unassigned here.