Fowler Denver Warwick
Dickinson Museum Center, Dickinson, North Dakota, United States of America.
PLoS One. 2017 Nov 22;12(11):e0188426. doi: 10.1371/journal.pone.0188426. eCollection 2017.
Interbasinal stratigraphic correlation provides the foundation for all consequent continental-scale geological and paleontological analyses. Correlation requires synthesis of lithostratigraphic, biostratigraphic and geochronologic data, and must be periodically updated to accord with advances in dating techniques, changing standards for radiometric dates, new stratigraphic concepts, hypotheses, fossil specimens, and field data. Outdated or incorrect correlation exposes geological and paleontological analyses to potential error. The current work presents a high-resolution stratigraphic chart for terrestrial Late Cretaceous units of North America, combining published chronostratigraphic, lithostratigraphic, and biostratigraphic data. 40Ar / 39Ar radiometric dates are newly recalibrated to both current standard and decay constant pairings. Revisions to the stratigraphic placement of most units are slight, but important changes are made to the proposed correlations of the Aguja and Javelina formations, Texas, and recalibration corrections in particular affect the relative age positions of the Belly River Group, Alberta; Judith River Formation, Montana; Kaiparowits Formation, Utah; and Fruitland and Kirtland formations, New Mexico. The stratigraphic ranges of selected clades of dinosaur species are plotted on the chronostratigraphic framework, with some clades comprising short-duration species that do not overlap stratigraphically with preceding or succeeding forms. This is the expected pattern that is produced by an anagenetic mode of evolution, suggesting that true branching (speciation) events were rare and may have geographic significance. The recent hypothesis of intracontinental latitudinal provinciality of dinosaurs is shown to be affected by previous stratigraphic miscorrelation. Rapid stepwise acquisition of display characters in many dinosaur clades, in particular chasmosaurine ceratopsids, suggests that they may be useful for high resolution biostratigraphy.
盆地间地层对比为所有后续的大陆尺度地质和古生物学分析奠定了基础。对比需要综合岩石地层、生物地层和地质年代数据，并且必须定期更新，以跟上测年技术的进步、放射性测年标准的变化、新的地层概念、假说、化石标本和野外数据。过时或不正确的对比会使地质和古生物学分析面临潜在的误差。当前的工作展示了一幅北美晚白垩世陆相地层的高分辨率地层图，整合了已发表的年代地层、岩石地层和生物地层数据。40Ar / 39Ar放射性测年数据已根据当前标准和衰变常数配对进行了重新校准。大多数地层单元的地层位置修订幅度较小，但对得克萨斯州阿古哈组和哈韦利纳组的对比提议有重要改动，重新校准校正尤其影响了艾伯塔省 Belly River 群、蒙大拿州朱迪思河组、犹他州凯帕罗维茨组以及新墨西哥州弗鲁特兰组和柯特兰组的相对年龄位置。选定恐龙物种类群的地层范围绘制在年代地层框架上，一些类群包含持续时间短的物种，它们在地层上不与之前或之后的物种重叠。这是由进化的前进演化模式产生的预期模式，表明真正的分支（物种形成）事件很少见，可能具有地理意义。最近关于恐龙大陆内部纬度分区的假说表明受到了先前地层错误对比的影响。许多恐龙类群，特别是开角龙亚科角龙类，显示特征的快速逐步获得表明它们可能对高分辨率生物地层学有用。
