Paleobiota of the Kristianstad Basin



The Kristianstad Basin is a Cretaceous-age structural basin and geological formation in northeastern Skåne, the southernmost province of Sweden. The sediments in the basin preserves a wide assortment of taxa represented in its fossil record, including the only non-avian dinosaur fossils in Sweden and one of the world's most diverse mosasaur faunas.

Though a majority of the taxa listed below lived during the latest early Campanian (c. 80.5 million years ago; fossils from the site Ivö Klack alone from this time compromise about 40 vertebrate species and more than 200 invertebrate species), the Kristianstad Basin preserves fossils ranging in age from the early Santonian (c.  86.3 million years ago) to the early Maastrichtian (c.  72.1 million years ago); some of the animals in the list were not contemporaries, but separated from each other in time by several million years. The time spans from which fossils have been recovered is included for each species in the list.

Crocodylomorphs
In addition to the remains referred to Aigialosuchus, detached and unidentified crocodylomorph scutes have also been discovered in Campanian-age deposits at Ivö Klack.

Birds
In addition to the fossils described below, indeterminate hesperornithiform remains have also been recovered from Åsen.

Plesiosaurs
The last comprehensive review of the plesiosaur fauna in the Kristianstad Basin was done by paleontologist Per-Ove Persson in the 1960s and his taxonomy is still used with caution, pending a much-needed new review.

Pterosaurs
Possible pterosaur bone fragments have been recovered from earliest Campanian-age deposits at Ullstorp, though they remain unpublished.

Scincomorpha
Fossils of terrestrial scincomorph lizards have been recovered in the Kristianstad Basin, but are as of yet unpublished.

Turtles
In addition to the fossils described below, indeterminate turtle remains, including limb bones and carapace fragments, have also been recovered from Ivö Klack, Ugnsmunnarna, Ignaberga and Åsen.

Invertebrates

 * Note: Although the Kristianstad Basin is incredibly rich in invertebrate fossils and diversity, with hundreds of species, the creation of a full list is impossible due to a lack of published overviews and recent examinations. Which lists are incomplete is specified below and estimates in regards to how many species are actually present are included if possible.

Bivalves
The bivalves are the most species-rich group present in the Kristianstad Basin, with Surlyk & Sørenson (2010) stating that close to 70 distinct species were present at Ivö Klack alone.

Brachiopods
According to Surlyk & Sørenson (2010) there were 27 distinct species of brachiopods present at Ivö Klack alone.

Bryozoans
Fossils of bryozoans are common in several sites throughout the Kristianstad Basin.

Ammonites
According to Surlyk & Sørenson, a large species of ammonite is also known from Ivö Klack.

Corals
Fossils of corals are common in several sites throughout the Kristianstad Basin. The list below only accounts for the recently revised diversity of corals found at Ivö Klack.

Crinoids
Fossils of crinoids have been found at several sites throughout the Kristianstad Basin.

Echinoids
According to Surlyk & Sørenson (2010) there were 18 distinct species of echinoids present at Ivö Klack alone.

Gastropods
According to Surlyk & Sørenson (2010), 19 species of gastropods could be identified from fossils just from the latest Early Campanian of Ivö Klack. Their subsequent 2011 study on the gastropods of the site only listed the 15 species accounted for below.

Polychaetes
In addition to the diverse polychaete worm fauna of Ivö Klack listed below, encrusters of serpulid polychaetes have also been discovered at Åsen, though they are considerably fewer in number there and as of yet unpublished.

Sponges
Fossil sponges have been recovered at fossil sites in the Kristianstad Basin.

Starfish
Fossils of starfish have been found at several sites in the Kristianstad Basin. According to Surlyk & Sørenson (2010) there were 16 distinct species of starfish present at Ivö Klack alone.