Preservation and Taphonomy of Fossil Insects from the Earliest Eocene of Denmark

The origins of colour patterns in fossil insects revealed by maturation experiments

Many fossil insects show monochromatic colour patterns that may provide valuable insights into ancient insect behaviour and ecology. Whether these patterns reflect original pigmentary coloration is, however, unknown, and their formation mechanism has not been investigated. Here, we performed thermal maturation experiments on extant beetles with melanin-based colour patterns. Scanning electron microscopy reveals that melanin-rich cuticle is more resistant to degradation than melanin-poor cuticle: with progressive maturation, melanin-poor cuticle regions experience preferential thinning and loss, yet melanin-rich cuticle remains. Comparative analysis of fossil insects with monotonal colour patterns confirms that the variations in tone correspond to variations in preserved cuticle thickness. These preserved colour patterns can thus be plausibly explained as melanin-based patterning. Recognition of melanin-based colour patterns in fossil insects opens new avenues for interpreting the evolution of insect coloration and behaviour through deep time.

Morphological and organic spectroscopic studies of a 44-million-year-old leaf beetle (Coleoptera: Chrysomelidae) in amber with endogenous remains of chitin

This study details the quality of preservation of amber deposits in the Eocene. Through Baltic amber crack-out studies using Synchrotron Micro-Computed Tomography and Scanning Electron Microscopy it was found that the cuticle of a specimen of leaf beetle (Crepidodera tertiotertiaria (Alticini: Galerucinae: Chrysomelidae)) is exceptionally well preserved. Spectroscopic analysis using Synchrotron Fourier Transform Infrared Spectroscopy suggests presence of degraded [Formula: see text]-chitin in multiple areas of the cuticle, and Energy Dispersive Spectroscopy supports the presence of organic preservation. This remarkable preservation is likely the result of several factors such as the favourable antimicrobial and physical shielding properties of Baltic amber as compared to other depositional media, coupled to rapid dehydration of the beetle early in its taphonomic process. We provide evidence that crack-out studies of amber inclusions, although inherently destructive of fossils, are an underutilised method for probing exceptional preservation in deep time.

Paleontology in the 21st Century

For much of its 300+ year history, "modern" paleontology has been a descriptive science, firmly housed within geological sciences [...].

A Plea for a New Synthesis: From Twentieth-Century Paleobiology to Twenty-First-Century Paleontology and Back Again

In this paper, I will briefly discuss the elements of novelty and continuity between twentieth-century paleobiology and twenty-first-century paleontology. First, I will outline the heated debate over the disciplinary status of paleontology in the mid-twentieth century. Second, I will analyze the main theoretical issue behind this debate by considering two prominent case studies within the broader paleobiology agenda. Third, I will turn to twenty-first century paleontology and address five representative research topics. In doing so, I will characterize twenty-first century paleontology as a science that strives for more data, more technology, and more integration. Finally, I will outline what twenty-first-century paleontology might inherit from twentieth-century paleobiology: the pursuit of and plea for a new synthesis that could lead to a second paleobiological revolution. Following in the footsteps of the paleobiological revolution of the 1960s and 1970s, the paleobiological revolution of the twenty-first century would enable paleontologists to gain strong political representation and argue with a decisive voice at the "high table" on issues such as the expanded evolutionary synthesis, the conservation of Earth's environment, and global climate change.