Showing papers by "Andrew D. Warren published in 2017"
TL;DR: It is hypothesized that although monocot feeding was an intrinsic trait that allowed exploration of novel niches, the lack of extensive availability of monocots comprised an extrinsic limitation for niche exploration.
Abstract: Skippers (Family: Hesperiidae) are a large group of butterflies with ca. 4000 species under 567 genera. The lack of a time-calibrated higher-level phylogeny of the group has precluded understanding of its evolutionary past. We here use a 10-gene dataset to reconstruct the most comprehensive time-calibrated phylogeny of the group, and explore factors that affected the diversification of these butterflies. Ancestral state reconstructions show that the early hesperiid lineages utilized dicots as larval hostplants. The ability to feed on monocots evolved once at the K-Pg boundary (ca. 65 million years ago (Mya)), and allowed monocot-feeders to diversify much faster on average than dicot-feeders. The increased diversification rate of the monocot-feeding clade is specifically attributed to rate shifts in two of its descendant lineages. The first rate shift, a four-fold increase compared to background rates, happened ca. 50 Mya, soon after the Paleocene-Eocene thermal maximum, in a lineage of the subfamily Hesperiinae that mostly fed on forest monocots. The second rate shift happened ca. 40 Mya in a grass-feeding lineage of Hesperiinae when open-habitat grasslands appeared in the Neotropics owing to gradual cooling of the atmospheric temperature. The evolution of monocot feeding strongly influenced diversification of skippers. We hypothesize that although monocot feeding was an intrinsic trait that allowed exploration of novel niches, the lack of extensive availability of monocots comprised an extrinsic limitation for niche exploration. The shifts in diversification rate coincided with paleoclimatic events during which grasses and forest monocots were diversified.
48 citations
TL;DR: Oxynetra aureopecta sp.
Abstract: Oxynetra aureopectasp. n. is described from the Sierra Madre Oriental of east-central Mexico. Visually similar to Mesoamerican O. hopfferi Staudinger, 1888 in having five orange bands on the abdomen above, it is diagnosed by orange forecoxae and palpi beneath, narrower forewing hyaline bands and a prominent 6% difference in the COI DNA barcode sequence. It is the northernmost representative of the hopfferi species group that also includes O. stangelandi Grishin & Burns, 2013, characterized by a single-banded abdomen and currently known only from the Area de Conservacion Guanacaste in northwestern Costa Rica. Both O. hopfferi and O. stangelandi possess white forecoxae and ventral palpi. This new discovery brings the total number of Oxynetra C. & R. Felder, 1862 species to five.
3 citations