Constellaria fischeri

Phylum: Bryozoa
Class: Stenolaemata
Order: Cystoporata
Genus: Constellaria
Species: Constellaria fischeri (Ulrich, 1883)

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Stratigraphic Occurrences

C. fischeri_strat

Geographic Occurrences

Map point data provided by iDigBio.
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Sequences (Formations)

  • C1 Sequence (Cynthiana)

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Identification in Hand Sample
C. fischeri ident

  • Zoariaum Morphology: Erect, flattened branches or fronts (frondose)
  • Zoecia: Polygonal
  • Mesozooids: More numerous in maculae
  • Monticules: Surface with depressed stellate (star-shaped) maculae
  • Spaces between rays elevated and occupied by rows of close apertures


Diagnosis: Surface usually smooth (sometimes slightly monticulated). Much smaller and more closely spaced (2-3x) maculae than C. florida (McFarlan, 1931).

Constellaria fischeri from unknown formation of Franklin County, Kentucky (CMCIP 18132)

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Karklins (1984):

  • Constellaria fischeri (Ulrich, 1883) Plate 35, figures 2-4; plate 40, figure 4
  • Constellaria fischeri (Ulrich, 1883), p. 270, pi. 14, figs. 6-6c; McFarlan,1931, p. 101, pi. 6, fig. 1; Utgaard, 1973, fig. 54.
  • Description: Zoaria dendroid, commonly having flattened, irregularly convoluted branches and occasionalsubcylindrical branches; conspecific overgrowth scattered locally. In endozones, autozooecia subparallel to branch axis, polygonal, generally three- to six-sided in cross section, curving abruptly, locally gradually, outward in outer endozones or inner exozones. Autozooecial walls slightly sinuous. Basal diaphragms generally sparse to absent, planar, occurring at right angles or slightly oblique to chamber axis. Basal diaphragms occasionally common in endozones of some zoaria. Zones of rejuvenation of autozooecia sparse.
  • In exozones, autozooecia generally at right angles to zoarial surface. Autozooecia in interstellar macular areas without preferred alignment, subcircular to circular, occasionally subpolygonal in cross section, partly contiguous to almost completely separated by vesicular deposits.
    Stellate maculae abundant, low, generally indistinct, occurring regularly or irregularly across zoarial surface.
  • Stellate maculae consisting of small, irregularly shaped areas of vesicular deposits in centers and of autozooecia clustered in approximately five to six rays. Ray clusters of autozooecia indistinctly defined, generally slightly longer than wide, separated by irregular strips of vesicular deposits, merging with autozooecia of interstellate macular areas and occasionally with adjacent rays. Ray clusters consisting of approximately 2 to 8, in rare instances up to 15, autozooecia. Ray clusters commonly subdivided longitudinally by indistinct partitions; midray partitions locally discontinuous or indistinctly bifurcating. Autozooecial walls straight to slightly sinuous, irregular in thickness locally. Autozooecial boundaries distinct. Basal diaphragms generally sparse to absent, planar to slightly curved, commonly concave distally, occurring at right angles or slightly oblique to chamber axis. Basal diaphragms locally common and evenly spaced in autozooecia of some zoaria. Autozooecial chambers circular to subcircular in cross section. Vesicular skeletal deposits abundant in centers of stellate maculae, occurring in narrow strips, irregular in width, between rays of maculae and commonly in interstellar macular areas. Vesicles small, polygonal in cross section, rectangular in profile, with thin walls. Chambers of vesicles partly filled by laminate skeletal deposits occasionally. Styles abundant to common throughout exozones, slightly variable in shape and size, occasionally expanding into irregular patches. Styles occurring mostly in walls of vesicles, in centers of stellate maculae, occasionally projecting into chambers of vesicles, commonly occurring in autozooecial walls. Nonlaminate skeletal deposits (yellow tissue of authors) abundant, occurring irregularly throughout exozones as styles, as midray partitions between autozooecia clustered in rays, as cylindrical deposits in autozooecial walls locally, and as scattered irregularly shaped skeletal patches.

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