In the summer of 2023, what seemed like tiny aliens turned up at the Wupatki National Monument. A visitor told park staff that tadpoles were wriggling about in a pool of standing water that had flooded the Ancestral Puebloan ballcourt.
With almost record-breaking winter snow and then spring melt, followed by healthy monsoon rains, park staff suspected there had been a hatching of toad tadpoles.
But when a ranger went to investigate, she had a surprise. The one- to two- inch long creatures resembled tiny pink horseshoe crabs, with three eyes and ribbed tails ending in two prongs.
They were Triops – sometimes called ‘dinosaur shrimp’ or living fossils because they show few differences from specimens found in rocks dating back to the Jurassic period, more than 140 million years ago.
Neither tadpoles, shrimp, nor insects, Triops are hexapods — six-legged creatures from the springtail family. Unlike insects, which have mouths on the outside, springtails chomp on their diet of fungi, insects, and plant detritus with mouthparts located inside their bodies.
Their tail-like appendage, called a furcula, is spring-loaded. When threatened, Triops use it to leap away, sometimes jumping hundreds of times their own body length to escape.
Triops eggs can remain dormant for decades in dry desert soils. Hatching when temporary ponds form, they grow to adulthood in just over a week, breed, lay more eggs and then hunker down... Waiting for the next wet summer.
This Earth Note was written by Diane Hope and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
