Observations with a scanning electron microscope demonstrate that basic to the structure of pennaceous feathers is the lamelliform structure of . Close up of the skull in the slab (a) and counterslab (b) of STM24-1. (a), right carpometacarpus; (b), proximal left tibiotarsus and fibula, caudal view; (c), right distal tarsometatarsus, dorsal view, scale bars = 5 mm. Furthermore, the specimen reveals morphologies that align it with the genus Pengornis, revealing a previously unrecognized lineage of enantiornithines. A, B, details of the remiges in STM24-1, scale bars = 5 mm. As in other pengornithids, the ulna is 115% the length of the humerus (subequal in Protopteryx; see Supporting Information, Table S1). [15], Rectrices are always numbered from the centermost pair outwards in both directions.[32]. However, as more complete specimens were discovered, these feathers were reinterpreted as modified pennaceous feathers (Yu et al., 2002; Zhang, Zhou & Dyke, 2006; O'Connor et al., 2012). The ungual of digit I is subequal in size to that of digit II but bears a larger flexor process. observ.) | Loons, grebes, pelicans, hawks and eagles, cranes, sandpipers, gulls, parrots, and owls are among the families missing this feather. 2E, F). 2H). [38] In the standard-winged nightjar, this modified primary consists of an extremely long shaft with a small "pennant" (actually a large web of barbules) at the tip. [2] Its basal part, called a calamus, is embedded in the skin. Dapingfangornis, Fig. [15] There are some advantages to each method. Language links are at the top of the page across from the title. UR - http://www.scopus.com/inward/record.url?scp=85036588173&partnerID=8YFLogxK. The pattern of feather drop and replacement proceeds as described for passerines (above) until all other rectrices have been replaced; only then are the central tail rectrices moulted. An ecological perspective on taxonomic, environmental and sexual determinants of phenotypic variation in big-eared woolly bats, Chrotopterus auritus, About Biological Journal of the Linnean Society, Receive exclusive offers and updates from Oxford Academic, Copyright 2023 The Linnean Society of London. D, forked tail (presumably formed by asymmetrical pennaceous feathers) in ornithuromorph Schizooura. Definition in the dictionary English. [22] These feathers may vary widely in size in fact, the upper tail tectrices of the male peafowl, rather than its rectrices, are what constitute its elaborate and colorful "train". The free cervical ribs are rod-like and as long as the centra. Proximally, in both feathers, the medial barbs form a larger angle (17 versus 10) with the rachis so that the width of the medial vane is much wider than that of the lateral vane (1.3 mm versus 3.7 mm). All the unguals preserve deep medial and lateral grooves; below the groove, the unguals bear lateral ridges. Simplified, open-vaned wing feathers were also observed on the oviraptorosaur Caudipteryx, consistent with, but not necessarily diagnostic of, its suggested flightlessness. Details of basal bird feathers. This adaptation is also found, though to a lesser extent, in some other species that feed along tree trunks, including woodcreepers and treecreepers. It may not have been reviewed by professional editors (see full disclaimer). A pennaceous feather has a stalk or quill. The numerical value of pennaceous feather in Chaldean Numerology is: 6, The numerical value of pennaceous feather in Pythagorean Numerology is: 5. The barbs are stiffer than in down feathers. All distance measurements are made with the bird's wing closed, so as to maintain the relative positions of the feathers. The English word games are: Most youngsters shed their claws sometime between their 70th and 100th day of life, but some retain them though callused-over and unusable into adulthood. As one of two of the oldest known enantiornithines, E. martini also helps to clarify poorly known early stages in the skeletal evolution of enantiornithines. Diversity is highest in the Jiufotang Formation: sapeornithiforms and jeholornithiforms are present in greater numbers and ornithuromorphs and enantiornithines are even more abundant (Zhou & Zhang, 2006a); the largest Lower Cretaceous enantiornithine, Pengornis houi (Zhou, Clarke & Zhang, 2008), is from this formation. The alular digit ends approximately level with the distal end of the major metacarpal and the ungual phalanx is larger than that of the major digit as in Pengornis IVPP V18632. The calamus is hollow and has pith formed from the dry remains of the feather pulp, and the calamus opens below by an . The lower Huajiying Formation, containing the Protopteryx-horizon, is the oldest geological unit to preserve fossil birds belonging to the Jehol Biota. We report on a new enantiornithine Eopengornis martini gen. et sp. Simplified, open-vaned wing feathers were also observed on the oviraptorosaur Caudipteryx, consistent with, but not necessarily diagnostic of, its suggested flightlessness. However, members . Combined with the interpretation of Anchiornis contour feathers, this suggests that differentiated barbicels are relatively derived compared to pennaceous feathers and the appearance of wings. Shaggy contour feathers probably influenced thermoregulatory and water repellence abilities, and, in combination with open-vaned wing feathers, would have decreased aerodynamic efficiency. Add your entry in the Collaborative Dictionary. This leaves them completely flightless for a period of three to four weeks, but means their overall period of vulnerability is significantly shorter than it would otherwise be. This forms a kind of miniature velcro-like mesh that holds all the barbs together, stabilizing the vanes. Similarly, the fibula remains long in Pengornis, whereas it is relatively more reduced in all other enantiornithines. The medial and lateral margins are only convex distally forming an expanded sternal margin. 5) (Clarke, Zhou & Zhang, 2006; Zhou, Zhou & O'Connor, 2012; Zheng et al., 2013b; Chiappe et al., 2014). They come in a variety of forms, the most familiar of which are remiges (flight feathers). In simple forms, this involves the moulting and replacement of odd-numbered primaries and then the even-numbered primaries. The presence of notches and emarginations creates gaps at the wingtip; air is forced through these gaps, increasing the generation of lift. The full pennaceous feather morphology in the basal enantiornithine Eopengornis suggests that the racket-plume morphology evolved in parallel within Enantiornithes and Confuciusornithiformes; alternatively, the tail feathers in Eopengornis could also represent a reversal to the basal condition. Feather types Comparison with Confuciusornis suggests that Anchiornis wing feathers were at least partially open-vaned. Contour feather Pennaceous feathers. [51], A wing formula describes the shape of distal end of a bird's wing in a mathematical way. (2012) hypothesized that along the proximal portion of the rachis cell fate was affected and the marginal plate cells that normally suffer apoptosis (Shh positive zones), creating the separation of individual barbs, survive, resulting in undifferentiated vane. 2B); they extend distally farther in Pengornis IVPP V18632 but do not reach the caudal margin in Protopteryx. observ.). Anatomical abbreviations: acr, acromion; bc, bicipital crest; cor, coracoid; l, left; lt, lateral trabecula; max, maxilla; mtI, metatarsal I; mtI 1, first phalanx of hallux; mtI 2, hallucal claw; mtII, metatarsal II; mtII 1, first phalanx of second digit; mtII 2, second phalanx of second digit; mtII 3, claw of second digit; mt III, metatarsal III; mtIII 3, third phalanx of third digit; mtIII 4, claw of third digit; mtIV, metatarsal IV; mtIV 5, claw of fourth digit; mtV, metatarsal V; sca, scapula; stn, sternum; st r, sternal ribs; th r, thoracic ribs; xr, xiphial region. Three to six sternal ribs articulated with the sternum. via a shared follicle), but lacking a rachis, is tentatively inferred. Comparative anatomy of Pengornithidae fam. Together, they form a new avian lineage that lasted over 10 Myr, which is longer than any known clade of Lower Cretaceous enantiornithine. nov. (Fig. The shaft becomes mediolaterally compressed just proximal to the expanded distal end. Given that basal birds were likely poor fliers and Jehol birds lived in a dense forested environment, high-speed flight was probably not an important part of the lifestyle of confuciusornithiforms and Jehol enantiornithines and their large ornaments might have come at minimal cost. However, conclusive morphological descriptions await the discovery of isolated Sinosauropteryx contour feathers. These feathers were originally interpreted as evidence that the feathers evolved from modified scales (Zhang & Zhou, 2000). The acromion is hooked ventrally, as in Pengornis, and almost as long as the lateroventrally facing glenoid (Fig. O'Connor et al. O'Connor et al. Summary Feathers are the most complex integumentary structures in the animal world. Please refer to any applicable terms of use of the publisher. The jugal is slightly shorter than the maxilla in length and rod-like. . STM24-1 further differs from the holotype of P. houi in size, degree of fusion of compound bones, and geological age; the much larger holotype is from the younger Jiufotang Formation, whereas the smaller STM24-1 comes from the lower member of the Jehol Biota, the first sedimentary member of the Huajiying Formation, thus the two specimens are separated by an estimated 10.7 Myr. These feathers are especially important for flapping flight, as they are the principal source of thrust, moving the bird forward through the air. Our hypothesis is grounded in the accepted phylogenetic framework for theropods, which shows that pennaceous feathers evolved before flight (1-3). In the pennant-winged nightjar, the P2 primary is an extremely long (but otherwise normal) feather, while P3, P4 and P5 are successively shorter; the overall effect is a broadly forked wingtip with a very long plume beyond the lower half of the fork. Powered by Pure, Scopus & Elsevier Fingerprint Engine 2023 Elsevier B.V. We use cookies to help provide and enhance our service and tailor content. We estimate the total number of cervical vertebrae to be nine or ten (only six preserved). 1), which is greater than that reported in any other enantiornithine. 3E) indicating that these rectrices can appear early in ontogeny (Zheng et al., 2012).