Cusplet
Also: lateral cusplet, lateral denticle, side cusp
A small, pointed projection flanking the main crown on some shark teeth. Prominent in early Otodus species and lost over time, cusplets help date a tooth and place it in the megatooth lineage.
A cusplet is a small, enamel-covered point that sits to either side of the main crown on certain shark teeth — think of a little shoulder beside the blade. They are prominent on early members of the Otodus lineage and on sand-tiger teeth, and their gradual disappearance is one of evolution's clearest fossil signatures.
Why cusplets matter for dating and lineage
Across millions of years the megatooth sharks lost their lateral cusplets: Otodus angustidens and O. chubutensis carry them, while true Megalodon teeth do not. Researchers have traced that loss as a gradual change over roughly twelve million years. Because of this, the presence, size, or absence of cusplets helps place a tooth in time and species. Our guide to the Otodus shark lineage traces that change step by step.
A note on authenticity
Cusplets are delicate and easily broken or, occasionally, faked, so on transitional specimens their condition is worth examining closely alongside the serrations and bourrelet.