Birds on the Brain

Scientists have now revealed arthropods trapped in 230-million-year-old amber from northeastern Italy, which appears to hold the most abundant outcrops of Triassic amber in the world. These are the oldest amber-trapped arthropods by about 100 million years, and are the first arthropods to be found in amber from the Triassic, they say….

One of the mites, Triasacarus fedelei [left], is just 210 microns long, or about twice the diameter of a human hair. Its distinctly wormlike shape suggests it may have lived in a tiny space that protected it from drying out. Its mouthparts are less fused together than the hypodermic-needlelike feeding structures of its modern counterparts — “these are probably an early progenitor of modern-day gall mites, a primitive form,” Grimaldi said.

The other, the 124-micron-long Ampezzoa triassica [right], had a more compact, spindle shape typical of mites with a vagrant lifestyle on exposed surfaces of plants. It apparently possessed waxy filaments on its surface, which may have protected it against predators and parasites, as well as from rain and drying out….

The ancient mites probably fed on the leaves of the extinct species of conifer tree whose resin ultimately preserved them. These fossil mites lived before the appearance of flowering plants, which about 97 percent of today’s gall mites now feed on.

(via 230-Million-Year-Old Mite Found in Amber | LiveScience)