The shallow marine carbonate deposits of the S. Miguel Formation in the Lusitanian Basin reveal erosional events exposing stiff substrates with abundant
Bergaueria hemispherica
. The ichnoassociation represented by
B. hemispherica
,
Thalassinoides suevicus
,
Spongeliomorpha
isp.,
Asterosoma ludwigae
and
Rhizocorallium commune
is dated from lowermost Pliensbachian by the association with ammonites from the
jamesoni
Biozone,
brevispina
Subzone. The unlined forms of
B. hemispherica
include peripheral and bottom burrow concentrations of shell debris, annular-like structures in the burrow margin and paired burrows-to-linear clusters that are comparable with the penetrative burrowing mechanism, anchoring and feeding behaviours of sea anemones. From the ethological point of view, and comparing with modern behaviours of burrowing anemomes, the
B. hemispherica
from the Lusitanian Basin may represent temporary burrowing and relocation of actiniarian anemones. Their comparison with either thenarian and athenarian actiniarians may evidence a preferred surficial feeding strategy on the organic-rich muddy sediments they burrowed.