Thoracic vertebrae of fossil taxa with lateral openings (lop) or pleurocoels (plc). A, Lithornis vulturinus from the early Eocene Fur Formation in Denmark (Lithornithidae; MGUH 26770). B, Primoptynyx poliotauros from the early Eocene of the Willwood Formation, Wyoming, USA (Strigiformes; UMMP 96195). C, Perplexicervix microcephalon from the latest early or earliest middle Eocene of Messel, Germany (SMF-ME 2559a). D, Telmabates antiquus from the early Eocene of Argentina (Presbyornithidae; AMNH 3170). E, Calcardea junnei from the late Paleocene of the Willwood Formation (UM 76882). F, Paraortygoides radagasti from the early Eocene London Clay of Walton-on-the-Naze, Essex, UK (Gallinuloididae; NHMUK A 6217). G, Tynskya waltonensis from Walton-on-the-Naze (Messelasturidae; SMF Av 652). H, Morsoravis sedilis from the Fur Formation (MGUH 28930). I, Parapsittacopes bergdahli from Walton-on-the-Naze (Psittacopedidae; SMF Av 653). J, Septencoracias cf. morsensis from Walton-on-the-Naze (Coraciiformes; SMF Av 655). The scale bars equal 5 mm.

 
 
  Part of: Mayr G (2021) On the occurrence of lateral openings and fossae (pleurocoels) in the thoracic vertebrae of neornithine birds and their functional significance. Vertebrate Zoology 71: 453-463. https://doi.org/10.3897/vz.71.e71268