Restinga Tyrannulet is a globally threatened Brazilian endemic that was described only as recently as the early 1990s. However, with hindsight, it was demonstrated that the first specimen was first collected in the late 19th century, by Ricardo Krone, who is commemorated in the scientific name of this species. Its plumage is similar to those of other Phylloscartes tyrannulets, being dull above with a faint yellowish supercilium, a blackish eyestripe, yellowish underparts, and pale yellowish wing bars, fringes, and tertial spots. This tyrannulet is largely restricted to restinga (coastal sand-ridge) vegetation on coasts, but also ranges inland into the foothills. The range of Restinga Tyrannulet extends from the state of São Paulo south to northern Rio Grande do Sul. This tyrannulet forages on small insects by sallying and gleaning, and often associates with roaming mixed-species flocks.