The Neocoleoidea, sister group to the Belemnoidea, includes all living ceph
alopod species except nautilids, as well as their immediate ancestors. Seve
ral hypotheses have been published about the morphology of ancestral neocol
eoids. Ancestral states are easily inferred from fossils for some character
s, such as 10 arms and the presence of an ink sac in basal coleoids or the
presence of fins in ancient octopods. Many inferences are less strongly sup
ported, though, and open to debate. We Examine this problem using three cla
dograms resulting from analyses of morphology and DNA sequences (both mitoc
hondrial and nuclear) from sampler representing the full diversity of erran
t coleoids. Character states at three ancestral nodes (neocoleoid, octopodi
-form, and decapodiform) are reconstructed for 51 morphological characters
using cladistic parsimony. Strong or moderate agreement among the three tre
es was found for almost 3/4 of the character-at-node reconstructions. The l
evel of agreement among the trees varied among nodes, with strongest agreem
ent found at the ancestral oetopodiform node. However. some of these recons
tructions seem unlikely to be correct. Changes in subclade resolution can e
xert varying effects on inferences about basal nudes. Because several subcl
ades within the neocoleoids are not yet adequately resolved, we cannot be v
ery confident in reconstructions of ancestral character states based solely
on parsimony and we propose a provisional suite of character-state reconst
ructions including other sources of inference in addition to parsimony.