Theoretical Article

Innovation directions in paleoecology:

evolutionary paleoecology

 

​

Hong-Xia Jiang^1*, Ya-Sheng Wu^2,3,4  Yue-Yang Zhang^2,4,5

¹Institute of Paleontology, Hebei Geo University, Shijiazhuang 050031, Hebei, China

²Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.

³Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China.

⁴University of Chinese Academy of Sciences, Beijing 100049, China.

⁵Natural Resources Monitoring Institute of Henan Province.

^*Corresponding author: jianghx@hgu.edu.cn.

Abstract

A new branch of paleoecology is defined here, evolutionary paleoecology, which covers the studies of the evolutions of the paleoecological habits of the taxa of all phyla in geological times. It is based on autecology and paleoautecology. The main methods in autecology are experiments and observations. More experimental studies are needed to determine what and how the environmental factors control the growth of taxa. The main paleoenvironmental factors for ancient taxa include the temperature, salinity, pH, DOT (dissolved oxygen content), and water-depth. The limitations of the methods to quantitatively determine the paleoenvironmental factors has hindered the development of paleoautecology. Many methods in the related disciplines, such as paleoatmospheric science, paleoceanography, paleogeography and sedimentology, can be used to quantitatively determine the paleoenvironmental factors. The urgent tasks in the future for paleoecologists are (1) to do more experimental researches in autecology, (2) to develop new methods for quantitatively determining paleoenvironmental factors, (3) to do researches on paleoautecology of taxa, (4) to do researches on evolutions of paleoautecological features of all taxa, and (5) to synthesize  the results of the paleoautecological studies of all taxa, to develop evolutionary paleoecology.

Crinoids are an example of the taxa whose paleoecology has changed in geological times. In the Paleozoic Era crinoids were abundant in shallow water environments, but in present-day oceans crinoids are sparse and distributed at depth from 105 to 5000 m.

Our statistical research on the Late Ordovician calcified dasycladaleans in the Tarim Basin shows that all of them occurred in shallow water sedimentary facies, such as the platform margin reefs, platform margin banks, and open platforms, but not in the restricted platform facies such as lagoons. According to our analysis on the literature on the calcified dasycladaleans from the times after the Ordovician, we found that the paleoecology of the calcified dasycladaleans has never changed since their appearance in the Late Ordovician.