72 research outputs found
The Earliest Evidence of Holometabolan Insect Pupation in Conifer Wood
Background: The pre-Jurassic record of terrestrial wood borings is poorly resolved, despite body fossil evidence of insect diversification among xylophilic clades starting in the late Paleozoic. Detailed analysis of borings in petrified wood provides direct evidence of wood utilization by invertebrate animals, which typically comprises feeding behaviors.\ud
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Methodology/Principal Findings: We describe a U-shaped boring in petrified wood from the Late Triassic Chinle Formation of southern Utah that demonstrates a strong linkage between insect ontogeny and conifer wood resources. Xylokrypta durossi new ichnogenus and ichnospecies is a large excavation in wood that is backfilled with partially digested xylem, creating a secluded chamber. The tracemaker exited the chamber by way of a small vertical shaft. This sequence of behaviors is most consistent with the entrance of a larva followed by pupal quiescence and adult emergence — hallmarks of holometabolous insect ontogeny. Among the known body fossil record of Triassic insects, cupedid beetles (Coleoptera: Archostemata) are deemed the most plausible tracemakers of Xylokrypta, based on their body size and modern xylobiotic lifestyle.\ud
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Conclusions/Significance: This oldest record of pupation in fossil wood provides an alternative interpretation to borings once regarded as evidence for Triassic bees. Instead Xylokrypta suggests that early archostematan beetles were leaders in exploiting wood substrates well before modern clades of xylophages arose in the late Mesozoic
Descriptive and Comparative Myology of the Forelimb of the Babirusa (Babyrousa babyrussa L. 1758)
subCULTron - Cultural Development as a Tool in Underwater Robotics
This paper presents the research done in the field of robotic cultural evolution in challenging real world environments. We hereby present these efforts, as part of project subCULTron, where we will create an artificial society of three cooperating sub-cultures of robotic agents operating in a challenging real-world habitat. We introduce the novel concept of “cultural learning”, which will allow a swarm of agents to locally adapt to a complex environment and exchange the information about this adaptation with other subgroups of agents. Main task of the presented robotic system is autonomous environmental monitoring including self organised task allocation and organisation of swarm movement processes. One main focus of the project is on the development and implementation of bio-inspired controllers, as well as novel bio-inspired sensor systems, communication principles, energy harvesting and morphological designs. The main scientific objective is to enable and study the emergence of a collective long-term autonomous cognitive system in which information survives the operational lifetime of individuals, allowing cross-generation learning of the society by self-optimising
L'incidence de la topographie sur la croissance d'une population de bouquetins en bordure des Alpes orientales
Scanning Electron Microscopic Observations on the Development and Structure of Tooth Enamel in Cervidae (Mammalia: Ruminantia)
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