BRYOZOANS FROM CHATHAM ISLAND 
CHATHAM ID 
PUKEKION,. 
oD 
PITT ID 
“ 
CHATHAM IDS 
Fig. 1 Simplified map of the Chatham Islands with the distribution of the 
Kekerione Group (Paleocene-Miocene), which includes the Red Bluff 
Tuff, marked in black (redrawn from Campbell et al., 1993: fig. 4.35) 
and the bryozoan locality Pukekio indicated. Inset map shows the 
position of the Chatham Islands relative to the mainland of New 
Zealand. 
(Campbell et al., 1993). At several localities (Waihere Bay on Pitt 
Island, Red Bluff and the coast south of Point Weeding to Pukekio 
Hill on Chatham island) the formation is reasonably accessible and 
can exceed 50 m in thickness. In high land south of Lake Huro it is 
around 100 m thick. 
The Red Bluff Tuff is a fossiliferous and largely marine unit 
belonging to the Kekerione Group. Fossil content includes spores, 
pollen, foraminifera, calcareous nannofossils, sponges, corals, 
bryozoans, brachiopods, bivalves, gastropods, nautiloids, barnacles, 
echinoderms, vertebrates (teeth), and trace fossils, with epifaunal 
assemblages dominating (Campbell ef al., 1993). Though reported 
as being present, the Bryozoa of the Red Bluff Tuff have never been 
described. The collection described here was made during a recent 
(February 1997) palaeontological expedition to the Chatham Islands 
(see Acknowledgments) and comes from Pukekio (Fig. 1), south- 
west of the radio station near Waitangi on the main Chatham Island 
(NZMS 260 Chatham Islands 1: 50 000 topographical map, 1981, 
grid reference 432540). The locality is New Zealand Fossil Record 
CH/f477. Determinations of foraminifera from Pukekio show the 
lower part of the formation to be late Teurian (= mid-Thanetian). The 
middle part of the formation ranges from early to late Waipawan (= 
latest Thanetian to earliest Ypresian). Whereas stratigraphy, cross- 
bedding, and textural characters suggest shallow-marine depositional 
conditions, fossil evidence is said to indicate mid-shelf to upper 
bathyal environments (Campbell ef al., 1993). 
COLONIAL MORPHOLOGY AND 
PALAEOECOLOGY 
Listed below are the 42 bryozoan species found in the Red Bluff Tuff 
with their colonial morphologies. 
Cyclostomata 
Stomatoporina sp. 
?Oncousoecia sp. 
‘Berenicea’ sp. 
?Idmidronea sp. 
‘Entalophorid’ sp. 
?Attinopora sp. 
Cinctipora solomoni sp. nov. 
Erect tubuliporine base sp. 1 
Erect tubuliporine base sp. 2 
Ceriopora rekohuensis sp. nov. 
?Tetrocycloecia sp. 
Disporella sp. 
Ctenostomata 
Immergentia sp. 
Cheilostomata 
Flustrellaria australis sp. nov. 
Akatopora chathamica sp. nov. 
Caleschara sp. 
Micropora quadriporosa sp. nov. 
?Hoplitaechmella sp. 
Microporid sp. 
Inversaria gondwanae sp. nov. 
Chondriovelum fossilis sp. nov. 
Ogiva incompta sp. nov. 
Onychocella? lamellosa sp. nov. 
2Onychocella sp. 
Onychocellid sp. 
Aspidostoma litotes sp. nov. 
Aspidostoma cinnabarina sp. nov. 
Cellaria minus sp. nov. 
Cellaria perexigua sp. nov. 
Cellaria elementaria sp. nov. 
Cellaria aff. depressa Maplestone 
Smitticellaria morioriana sp. nov. 
?Escharicellaria sp. 
Melychocella cynura sp. nov. 
Arachnopusia gracilis sp. nov. 
?Pavobeisselina sp. 
Hippopleurifera australis sp. nov. 
Exochella? gracilis sp. nov. 
Escharoides? crassa sp. nov. 
Lepraliellid sp. 1 
?Lepraliellid sp. 2 
Chataimulosia primaeva sp. nov. 
encrusting, runner 
encrusting, runner 
encrusting, patch/sheet 
fixed-erect, planar tree 
fixed-erect, tree-like 
fixed-erect, tree-like 
fixed-erect, tree-like 
fixed-erect, ?tree-like 
fixed-erect, ?tree-like 
encrusting, mound 
fixed-erect, tree-like 
encrusting, patch 
shell-boring, runner 
encrusting, patch/sheet 
encrusting, patch/sheet 
encrusting, patch/sheet multi- 
lamellar 
encrusting, patch 
encrusting, patch 
?fixed-erect, ?rod/?planar tree 
fixed-erect, tree-like 
?fixed-erect, tree-like 
?fixed-erect, planar tree 
encrusting, patch/sheet/mound/ 
multilamellar 
encrusting, patch/sheet 
?encrusting, ?patch/sheet 
fixed-erect, ?tree-like 
encrusting, patch/sheet 
flexible-erect, tree-like 
flexible-erect, tree-like 
flexible-erect, tree-like 
flexible-erect, tree-like 
?flexible-erect, planar tree 
?flexible-erect, planar tree 
?flexible-erect, ?rod/?planar 
tree 
fixed-erect, ?rod/?planar tree 
rooted, lobate 
encrusting, patch/sheet 
fixed-erect, ?rod/planar tree 
encrusting, patch/sheet 
encrusting, patch/sheet 
self-encrusting, free, multi- 
lamellar 
encrusting, patch/sheet 
There is some margin of error in interpreting colonial morphologies 
owing to the incompleteness of colony fragments. Almost 50% of 
the 42 species are surface encrusters, predominantly those forming 
more-or-less circular patches or sheets. Only ca. 7% (excluding the 
shell-boring species) of the fauna consists of ramifying, runner-like 
colonies. Some 46% of the fauna are erect species, of which slightly 
less than half were probably basally rooted, allowing for bending of 
whole colonies in a current. The proportional representation of 
colonial morphologies in the Red Bluff Tuff fauna can be compared 
with bryofaunas from other settings (Table 1). 
Although encrusters dominate taxonomically the bryofauna in the 
