Table 1. Summary statistics for lengths and widths of fossil ancestrulae measured in this study. N = number of colonies measured, W = width and L = length of ancestrula in mm. All- Dekayia  = measures for all genera with Dekayia removed, because it was statistically smaller than the others

Figure 3. Early colony budding patterns in four genera of Upper Ordovician bryozoans. 1, Dekayia sp.; 2, deep section from specimen (L28.6) of Dekayia sp. displaying helically-shaped protoecial flange; 3, shallower section (L28.4) of Dekayia sp., located 0.10 mm above previous one

Figure 6 1–7 , Dekayia sp.: 1–3 , CEGH-UNC 25213, longitudinal section showing autozooecia and mesozooecia; 4 , 5 , CEGH-UNC 25214, tangential section showing autozooecial apertures, mesozooecia and acanthostyles; 6 , 7 , CEGH-UNC 25213, longitudinal section showing cyst-like

Table 3 Descriptive statistics of Dekayia sp. Abbreviations as in Table 1 .

Figure 8. Intercolony fusion, or homosyndrome, in Dekayia aspera. 1 , transverse section (W25.4) with arrow indicating the contact boundary between two colonies (accented by color differences) developed from separate ancestrulae; 2 , shallower (W25.3) transverse section, 0.05 mm above previous

Figure 1 Examples of reassembled colonies from the seven species used in this study. ( 1 ) Batostomella gracilis , OSUN 2. ( 2 ) Stigmatella sp., OSUN 9. ( 3 ) Dekayia aspera Milne-Edwards & Haime, 1851 , OSUN 4. ( 4 ) Constellaria florida, CMC IP72750. ( 5 ) Hallopora andrewsi

of Parvohallopora coincides with the box's lower boundary; 2 , ancestrular lengths (mm). The width of Dekayia (smaller) differs statistically from that of Parvohallopora . Summary statistics, and the probabilities of equal widths and lengths between genera, are listed in Tables 1 and 2 , respectively.

Figure 5 ( 1 ) Parvohallopora sp. (MPZ 2013/251), longitudinal section of the colony in the initial massive growth stage. ( 2–4 ) Dekayia sp. (MPZ 2013/166); ( 2 ) tangential section showing the irregularly polygonal autozooecial cross section, the scarce

(Maysvillian), Ordovician, Covington, Kentucky; two endozonal styles, maculum with mesopores in center, ×30. 4, Dekayia maculata James, 1881 , holotype (USNM 146296), upper Eden Shales, Loveland, Ohio; endozonal style and zooecial style, ×30

of zooecium from endozone and beginning of style at arrow, exozonal style below, longitudinal, ×100; 5, USNM 526049, styles have sharp core boundaries, some centered in typical petaloid arrangement of autozooecia, tangential, ×30. 6, 7, Dekayia aspera , Milne-Edwards and Haime, 1851 , type species

CMC IP72749, CMC IP72755, OSUN 6 Dekayella ulrichi CMC IP72751, OSUN 7, OSUN 8 Homotrypa obliqua OSUN 3 Dekayia aspera OSUN 4, OSUN 5 Stigmatella sp. OSUN 9