Zemes un vides zinātnes Earth and Environment Sciences - Latvijas ...

100 ADVANCES IN PALAEOICHTHYOLOGY
from the Pavāri site were for the first time excavated by Lyubov Lyarskaya in 1970, and
the geological setting of the Ketleri Formation was defined and stratigraphical
conclusions were made together with Lyudmila Savvaitova (Lyarskaya and Savvaitova
1974). In subsequent years excavations were organised by L. Lyarskaya (in 1973), and
by E. Lukševičs in cooperation with palaeontologists from the Natural History Museum
of Latvia, Museum of Natural History (London), Palaeontological Institute (Moscow),
Cambridge University, Institute of Petroleum Geology (Novosibirsk), in 1988, 1989,
1991, 1995, and finally in 2001, adding significantly to the vertebrate material. Some
palaeoecological clues analysing the faunal composition and taphonomical features of
the Ketleri and Pavāri localities have been made previously (Lukševičs 1992), and
notes on the faunal composition were published together with the first description of
Ventastega (Ahlberg, Lukševičs and Lebedev 1994). The fossil assemblage of the Pavāri
site is important for the understanding of palaeoecology of the Late Devonian vertebrates
in the Baltic palaeobasin. Now the Pavāri locality is a Nature Monument still under
active study; some sedimentological and taphonomical studies were carried out there
in 2001, 2002 and 2004 by the authors of this article. The present paper provides a
more complete description of the geology, taphonomy and faunal composition of the
Pavāri site.
Material and methods
The Ketleri Formation is distributed only in southwestern Latvia and northwestern
Lithuania, cropping out only along the northern margin of its distribution in Latvia.
Two localities of the Ketleri Formation are particularly rich in vertebrate fossils: the
Ketleri site at the river Venta near the former Ketleri hamlet and the Pavāri site at the
river Ciecere opposite the former Pavāri hamlet. The Pavāri site is located in the southern
corner of the Kuldīga district, in western Latvia (Fig. 1). The best fossils come from the
Pavāri site, where more than a thousand specimens of fossil vertebrates were excavated
during several field seasons. Vertebrate fossils were collected mainly to examine the
faunal composition of the assemblage and the morphology of the various taxa, but in
1988 and 2001, also to collect taphonomic and sedimentological information. More
than 900 specimens have been determined to the generic/species level. The distribution,
sorting, orientation, state of preservation, and wearing of vertebrate remains have also
been studied. Data on spatial distribution, sorting and azimuthal orientation of fossil
bones and skeletal fragments were collected in 1988 and 2001; totally 325 measurements
of the orientation of fossil bones were taken. More than 800 specimens stored at the
Natural History Museum of Latvia were examined to detect the state of preservation
and wearing of bones.
A complete grain size analysis of seven rock samples from the Ketleri Formation
was carried out. The content of clay and silt was detected using the pipette method at
the Laboratory of Quaternary Environment and Laboratory of Soil Research at the
Faculty of Geographic and Earth Sciences of University of Latvia. Sand particles were
sieved at the laboratory of the Institute of Silicate Technology at the Riga Technical
University using a set of „Fritsch” sieves „Analysette 3PRO”. MS Excel was used to
run the statistical analysis of the data. Variation and cumulative curves were drawn to
illustrate the granulometric composition of the rocks, and the coefficient of sorting and