Sometimes it helps to seek out the original material.
"The relatively loosely vaned pennaceous feather that the hard tick described herein is grasping (Fig.
1; Supplementary Fig.
1) shows barbule pennula with hooklets in some areas. This would assign the feather to stage IV in Prum’s evolutionary-developmental model of the feather, but the clear length asymmetry between the barbs on either side of the rachis classifies it within stage V27. Even though stage IV and V feathers have for the most part been inferred in the fossil record, namely in compression fossils through the presence of well-developed closed vanes, some directly visible instances of these stages in Cretaceous amber feathers were previously reported (although not figured or poorly so) bearing barbules with hooklets like the ones presented here28, 29. These structures have not been described from other Cretaceous feathers found in Burmese30, 31, Canadian32, or Spanish ambers. Furthermore, stage IV feathers have been associated with taxa adapted for gliding or powered flight due to the ability of the barbules to interlock and allow for closed feather vanes27, but as the latter are also found in cursorial taxa they do not directly imply gliding or flying ability33. In any case, a feather belonging to the stage V indicates that the dinosaur host of the hard tick described herein falls within the clade Pennaraptora according to current evidence from the fossil record of feathered dinosaurs (see Supplementary Note
4). Crown-group birds are excluded as possible hosts because their inferred age is significantly younger than Burmese amber, i.e., about 73 Ma based on targeted next-generation DNA sequencing34. Even if the palpal claws of
Cornupalpatum were interpreted as a possible adaptation to parasitism of an extinct line of reptilian hosts12, at least the nymphs ectoparasitised feathered dinosaurs based on the direct evidence provided herein, although this hard tick species could have also parasitised other hosts."
parasitised feathered dinosaurs as revealed by Cretaceous amber assemblages