Marine reptiles of the Late Jurassic oceans - Liopleurodon (166-155mya) and Plesiosaurs (215-66mya).
Diet - mainly fish and invertebrates, although liopleurodon was large enough to also tackle ichthyosaurs.

You will need two skeins of yarn in contrasting colours, my square weighs c.55 grams.

The pattern is 47sts by 58 rows done in double knitting, and comes out at 10 inches square on 4mm needles.

You could use thicker yarn and larger needles for a larger square if you wish.