EXPANDING THE RECORD OF LARVAE OF FALSE FLOWER BEETLES WITH PROMINENT TERMINAL ENDS

Beetle larvae contribute to the overall biomass with a great share, yet they often stay unnoticed and underexplored. Larvae of the group Scraptiidae, also called false flower beetles, lead a life hidden in the wood, not easily accessible for observers. There, they contribute to wood decomposition and carbon cycling. Even though their ecological role is of great importance, these larvae have been comparably rarely studied. This is true for extant as well as fossil representatives of this group. It seems that this knowledge gap is not based on the limited availability of material but results from insufficiently studied material. Here we report new specimens, of which seven are extant and twelve are fossil. Fossil specimens are either from 40-million-year-old Baltic amber (Eocene) or 100-million-year-old Myanmar amber (Cretaceous), the latter representing the oldest record of these larvae. All specimens considered here possess a large, elongated terminal end. We performed an outline analysis of the shape of this terminal end for all so far known larval specimens sufficiently well preserved (in total 33 specimens: 17 extant, 14 Eocene, 2 Cretaceous). There is a recognisable difference between Eocene and extant specimens, yet it remains unclear whether this is due to different represented larval stages or an effect of evolution.

Crown outline analysis of the hominin upper third molar from the Megalopolis Basin, Peloponnese, Greece

The left upper third molar from the Megalopolis Basin is enigmatic due to its problematic preservation and context. The Megalopolis molar is the only possible human fossil known to date from the Megalopolis Basin. It was found on the surface during geological surveys in 1962-63. Based on the faunal assemblage collected during the same survey, it was proposed to be of Middle Pleistocene age and possibly one of the oldest human fossils in Europe. However, its actual geological age is unknown. In the past, dental crown outline analysis has been successfully used to differentiate between hominin species and populations. We applied the method to upper third molars, attempting to shed light on the affinities of the Megalopolis specimen. Principal component analysis (PCA) of the crown outline shape grouped the Megalopolis molar with our Homo sapiens sample; however, the PCA in form space, including shape plus size, as well as Procrustes distances based on overall shape, grouped it with our Neanderthal comparative sample. We conclude that its most likely identification is as a member of the Neanderthal lineage. However, we urge further analyses with an increased fossil comparative sample to include representatives of Homo heidelbergensis, which is underrepresented in our study. The Megalopolis molar contributes to the scarce Pleistocene human fossil record of Greece and highlights the potential of the Megalopolis Basin for yielding further paleoanthropological finds.

Split-footed lacewings declined over time: indications from the morphological diversity of their antlion-like larvae

Nymphidae, the group of split-footed lacewings, is a rather species-poor group. Split-footed lacewings nowadays are restricted to Australasia, while fossil forms are also known from other areas of the world, indicating that the group was more species-rich and therefore likely diverse in the past. Split-footed lacewings have rather distinct larvae, roughly resembling antlion larvae, but differing from the latter especially with regard to the mandibles. Antlion larvae usually have three prominent teeth on each mandible, while at least extant larvae of split-footed lacewings only have a single prominent tooth per mandible. Fossils interpreted as larvae of split-footed lacewings are well known from amber from Myanmar (ca. 100 myr; Burmese amber) and by a single specimen from Baltic amber (about 40 myr). We here report additional fossil specimens from Myanmar amber, expanding the known record of fossil forms from six depicted specimens to 15. For the extant fauna, we could compile 25 larvae. We compare the diversity of shape of extant and fossil larvae through time using an outline analysis (based on elliptic Fourier transformation) of the head. The results of this analysis indicate that the morphological diversity, or disparity, of split-footed lacewing larvae was higher in the past than it is today. With this type of analysis, we can show a loss of diversity over time, without the necessity to identify the fossil larvae down to a narrow taxonomical range. A similar pattern has already been recognised in silky lacewings, Psychopsidae. This might indicate a general loss of diversity of lacewing larvae.

Geometric morphometric analysis of different species of Cyprideis deriving from the Early Pleistocene record of Greece.

<p>The genus Cyprideis is one of the most widespread ostracod representative of the Pleistocene brackish palaeoenvironments. Especially <em>Cyprideis torosa </em>is often found in great numbers and even in monospecific taphocoenoses and for this reason its study is very useful for palaeoenvironmental reconstructions.  The identification of different species of Cyprideis is often complicated and needs careful morphology inspection. This becomes even more difficult in the case of endemic species which present significant similarities with each other.  In this work, we have studied and analyzed several  Cyprideis species (<em>C.torosa, C. frydaci, C.dictyoti, C. pannonica, C. elisabeta, C. seminulum, C. heterostigma</em>) deriving from brackish palaeoenvironments of a Lower Pleistocene marl sequence in Sousaki Basin (Northeastern Corinth Graben, Greece). More specifically size measurements and geometric morphometrics (lateral valve outline of both right and left valves as well as females and males) were used in order to attest the similarities and dissimilarities between the different species and draw conclusions about their origin.  According to the valve outline and the multivariate analysis a close relationship between the valve shape of all Cyprideis species can be noticed. <em>C. torosa</em> is commonly grouped with <em>C. pannonica</em> except in the male right valve where the two species show some differences.  The endemic species <em>C. frydaci</em> and <em>C. dictyoti</em> can be identified by the differences in the right valve of the male and female respectively.  The other species could not be substantially differentiated using just the outline analysis which possibly denotes their common genetic origin.  The valve outline has proved to be a very useful character for recognizing the different species especially when the two valves of both females and males are considered. More analyses of representative species of Miocene and Pliocene Cyprideis are needed in order to establish their phylogenetic relationships and draw conclusions about their common ancestor.</p>

Botanical Digitization: Application of MorphoLeaf in 2D Shape Visualization, Digital Morphometrics, and Species Delimitation, using Homologous Landmarks of Cucurbitaceae Leaves as a Model

ABSTRACTMorphometrics has been applied in several fields of science including botany. Plant leaves are been one of the most important organs in the identification of plants due to its high variability across different plant groups. The differences between and within plant species reflect variations in genotypes, development, evolution, and environment. While traditional morphometrics has contributed tremendously to reducing the problems that come with the identification of plants and delimitation of species based on morphology, technological advancements have led to the creation of deep learning digital solutions that made it easy to study leaves and detect more characters to complement already existing leaf datasets. In this study, we demonstrate the use of MorphoLeaf in generating morphometric dataset from 140 leaf specimens from seven Cucurbitaceae species via scanning of leaves, extracting landmarks, data extraction, landmarks data quantification, and reparametrization and normalization of leaf contours. PCA analysis revealed that blade area, blade perimeter, tooth area, tooth perimeter, height of (each position of the) tooth from tip, and the height of each (position of the) tooth from base are important and informative landmarks that contribute to the variation within the species studied. Our results demonstrate that MorphoLeaf can quantitatively track diversity in leaf specimens, and it can be applied to functionally integrate morphometrics and shape visualization in the digital identification of plants. The success of digital morphometrics in leaf outline analysis presents researchers with opportunities to apply and carry out more accurate image-based researches in diverse areas including, but not limited to, plant development, evolution, and phenotyping.

Standardization of ceramic shape: A case study from the Iron Age pottery from northeastern Taiwan

The emergence of ceramic specialization in prehistoric societies is often linked to shifts in the complexity of social structures, because standardized ceramic production can reflect craft specialization and the presence of elite control. Previous work on identifying specialization relies on typological or linear metric analysis. Here we demonstrate how to investigate ceramic standardization by analyzing outlines of ceramic vessels. Outline analysis is useful because, unlike more commonly-used landmark analysis methods, it can effectively quantify shape differences for objects that lack distinctive measurement points needed for landmark analysis. We demonstrate this method using pottery from Kiwulan, a large multi-component Iron Age site (AD 1350-1850) in northeastern Taiwan. To measure ceramic specialization, we quantified pottery standardization by analyzing shape variables with reproducible geometric morphometric methods. We computed coefficients of variation (CVs) for shape coefficients obtained by elliptical Fourier analysis to test for shape standardization. We found significant differences in pottery shape and shape standardization that indicate changes in pottery production resulting from contact with mainland Han Chinese groups in northeastern Taiwan. Our case study, which includes an openly available research compendium of R code, represents an innovative application of outline-based methods in geometric morphometry to answer the anthropological questions of craft specialization.

Morphometric assessment of pterosaur jaw disparity

Pterosaurs were a successful group of Mesozoic flying reptiles. They were the first vertebrate group to achieve powered flight and varied enormously in morphology and ecology, occupying a variety of niches and developing specialized feeding strategies. Ecomorphological principles suggest this variation should be reflected by great morphological diversity in the lower jaw, given that the mandible served as the primary apparatus for prey acquisition. Here we present the first study of mandibular shape disparity in pterosaurs and aim to characterize major aspects of variation. We use a combination of geometric morphometric approaches, incorporating both outline analysis using elliptical Fourier analysis and semi-landmark approaches. Our results show that morphological convergence is prevalent and many pterosaurs, belonging to diverse dietary groups and subclades, overlap in morphospace and possessed relatively simple ‘rod-shaped’ jaws. There is no clear trend of size distributions in pterosaur mandibular morphospace, and larger forms are widely distributed. Additionally, there is limited functional signal within pterosaur lower jaw morphospace. Instead, the development of a large anterior ventral crest represents the major component of disparity. This suggests that a socio-sexual trait was a key driver for innovation in pterosaur lower jaw shape.