DOI: 10.5061/dryad.ct40s
title: Data from: Measurement, variation, and scaling of osteocyte lacunae: a case study in birds

description: Basic issues surrounding osteocyte biology are still poorly understood,
 including the variability of osteocyte morphology within and among bones,
 individuals, and species. Several studies have suggested that the volume
 or shape of osteocytes (or their lacunae) are related to bone and/or
 organismal growth rate or metabolism, but the nature of this relationship,
 if any, is unclear. Furthermore, several studies have linked osteocyte
 lacuna volume with genome size or growth rate and suggested that osteocyte
 lacuna volume is unrelated to body size. Herein the scaling of osteocyte
 lacuna volume with body mass, growth and basal metabolic rates, genome
 size, and red blood cell size is tested using a broad sample of extant
 birds within a phylogenetic framework. Over 12,000 osteocyte lacuna axes
 were measured in a variety of bones from 34 avian and four non-avian
 dinosaur species. Osteocyte lacunae in parallel-fibered bone are scalene
 ellipsoids; their morphology and volume cannot be reliably estimated from
 any single thin section, and using a prolate ellipsoid model to estimate
 osteocyte lacuna volume results in a substantial (ca. 2–7 times)
 underestimate relative to true lacunar volume. Orthogonal thin sections
 reveal that in birds, even when only observing parallel-fibered, primary,
 cortical bone, intra-skeletal variation in osteocyte lacuna volume and
 shape is very high (volumes vary by a factor of 5.4 among different
 bones), whereas variation among homologous bones of the same species is
 low (1.2–44%; mean = 12%). Ordinary and phylogenetically informed
 bivariate and multiple regressions demonstrate that in birds, osteocyte
 volume scales significantly but weakly with body mass and mass-specific
 basal metabolic rate and moderately with genome size, but not with
 erythrocyte size. Avian whole-body growth rate and osteocyte lacuna volume
 are weakly and inversely related. Finally, we present the first
 three-dimensionally calculated osteocyte volumes for several non-avian
 dinosaurs, which are much larger than previously reported values and
 smaller than those of large extant avians. Osteocyte volumes estimated
 from a single transverse section and assuming prolate morphology, as done
 in previous studies, are relative underestimates in theropod dinosaurs
 compared to sauropod dinosaurs, raising the possibility that no major
 change in osteocyte volumes (and genome size) occurred within Theropoda on
 the lineage leading to birds. Osteocyte volume is intertwined with several
 organismal attributes whose relative importance varies at a number of
 hierarchical levels.
description: Input
 DataInput data includes
 osteocyte lacuna measurements for extant birds, extinct dinosaurs, and
 humans (human data from McCreadie et al., 2004). Also included: avian life
 history attributes, avian phylogeny employed in this study, and R
 script.Input
 data.zipOutput
 dataDinosaur lacuna
 imagesFile contains images of
 thin sections of dinosaur bones analyzed in this study. Measured lacunae
 were labeled using ImageJ. Abbreviations: fem = femur, long = photograph
 of a longitudinally oriented thin section, tib = tibia, xs = photograph of
 a thin section representing part of a cross section of a
 bone.Accipiter cooperi femur
 242198Accipiter striatus femur
 242034AccipiterCooperi
 241009AccipiterStriatus
 240638Aegolius 241878
 femurAeoglius 241878
 humerusBonasa
 242039Branta
 227638Bubo
 R1452Cardinalis
 241794Colaptes
 241887Carduelis
 241809Cyanocitta femur
 242057Colaptes humerus
 241887Cyanocitta
 241803Cyanocitta241803.zipDendroica 240871Dendroica 241982Diomedea 210390Grus 116250Dumetella femur 242013Icterus 241804Larus femur 8771Meleagris R1718Otus 240864Otus 241793 femurOtus 241793 humerusParus femur 241934Parus humerus 241963Parus femur 241963Passerella 243058Phalacrocorax idahoensis63156Phalacocrorax idahoensis63156.zipPhalacrocorax idahoensis74435Pheucticus femur 241935Pheucticus femur 241952Piranga 241960Podilymbus 8725Quiscalus 241885Rhea 223136Sitta 241779Spizella 241938Struthio fem R1716Struthio hum R1716Turdus 241899Vermivora femur 242012Vireo 240779Zonotrichia 241280Dromaius R1717 cervical vertZenaita 241897Zenaida 241897.zipDromaius R1717 coracoidDromaius R1717 caudal vertDromaius R1717 dorsal ribDromaius R1717 femurDromaius R1717 fibulaDromaius R1717 frontalDromaius R1717 furculaDromaius R1717 humerusDromaius R1717 ischiumDromaius R1717 metacarpalsDromaius R1717 pedal phalanxDromaius R1717 pedalphalanx.zipDromaius R1717 manual phalanxDromaius R1717 scapulaDromaius R1717 pubisDromaius R1717 radiusDromaius R1717 scleral ossicleDromaius R1717 tarsometatarsusDromaius R1717 sternal ribDromaius R1717 tibiotarsusDromaius R1717 ulnaReadme_DEmicBenson