INSTITUTE OF GEOLOGY
CROATIA, Zagreb, Sachsova
In Croatia (cf. Map), for more than a century fossil algae have been found and
described in carbonate rocks ranging in age from Upper Carboniferous to Palaeocene. This discussion is a brief
review of the associations of Dasycladalean algae from the Middle and Upper
Triassic, with emphasis on the stratigraphical ranges of some species or
associations (cf. Table). Each species and subspecies is described
The first association occurs in the lowermost Anisian (?Aegean). It includes Diplopora cellulata,
Poncetella helvetica, Poncetella hexaster, and Diplopora proba (Aegean-Pelsonian), as well as Diplopora subtilis (Aegean-Lower Illyrian).
Higher in the succession (?Bithynian) a Physoporella - Oligoporella association appears. It includes:
Physoporella pauciforata var. pauciforata, Ph. pauciforata var. sulcata,
Ph. pauciforata var. undulata, Oligoporella cornuta (= Ol. pilosa var. varicans),
Ol. dissita (= Ph. dissita), Ol. minutula (= Ph. minutula), Ol. pilosa var. intusannulata,
Ol. pilosa var. pilosa, Ol. praealpina (= Ph. praealpina), and Ol. varicans (= Ph. varicans)
(after GRGASOVIĆ, 1995).
The Oligoporella - Physoporella association, together with Macroporella alpina, has its maximum
development in the Pelsonian and Lower Illyrian. Physoporella croatica (Pelsonian) andTeutloporella tabulata
(Pelsonian - Lower Illyrian) also occur in this interval, as well as Scinderella scopuliformis and
Teutloporella peniculiformis, which is common throughout the whole of the Pelsonian-Fassanian.
Although less abundant than the species listed above, Euteutloporella triasina, Diplopora nodosa and
Diplopora annulatissima (in the "classical" form, and in the form of Favoporella annulata)
have been found in strata dated Lower Illyrian. Along with Macroporella beneckei these three species have their maximum
development in the Upper Illyrian and Fassanian.
The Anisian - Ladinian boundary is marked by the appearance of Diplopora annulata and Kantia dolomitica ,
both common throughout the Ladinian. During the Fassanian they are associated
with the above-mentioned Illyrian species, as well as the rarer Physoporella lotharingica and Clavapora
clavaeformis. In the Langobardian (?) they are associated with Teutloporella herculea and the less common
Euteutloporella triasina and Diplopora nodosa.
The Carnian is characterised by Clypeina besici, Physoporella jomdaensis,
Dissocladella bystrickyi and Griphoporella curvata.
Gyroporella vesiculifera appears in the Norian, and along with Gryphoporella curvata
is abundant in Rhaetian beds together with the foraminifer Triasina hantkeni.