http://hdl.handle.net/10174/999 Fri, 04 Sep 2026 20:17:17 GMT 2026-09-04T20:17:17Z http://hdl.handle.net/10174/42537 Title: Can arthropods produce Paleodictyon? Authors: Baucon, Andrea; Neto de Carvalho, Carlos; Uchman, Alfred; Lo Russo, Girolamo; Guerrini, Filippo; Moreira, Noel; Meloni, Mattia Alessio; Barucci, Andrea; Piazza, Michele Abstract: Paleodictyon is a common structure documented in marine sediments from the Cambrian to the present times. Despite its pervasive distribution and distinctive hexagonal geometry, the tracemaker remains unidentified. This study investigates the hypothesis that a marine arthropod could be responsible for its production. We assess this hypothesis by reviewing six key characteristics of Paleodictyon: morphology, stratigraphic distribution, envi¬ ronmental distribution, taphonomy, tracemaker attributes, and inferred function. Arthropods are well-known for creating straight tunnel segments, a capability afforded by their jointed appendages and rigid exoskeletons, which also facilitate sharp directional changes. These attributes are consistent with the straight burrow segments of Paleodictyon, which converge at 120◦ angles. In contrast, worm-like organisms, characterised by their cylin¬ drical body plan and hydrostatic skeletons, tend to create more tortuous burrows because burrowing proceeds preferentially along paths of least resistance. A review of published evidence suggests that the tracemaker was likely highly motile and, if solitary, an exceptionally rapid burrower. Morphometric analysis of 1314 landmarks shows that interior angles depart from 120◦ by only 8.5◦ and side lengths vary within each cell by 0.5 mm. Rather than propagating errors between cells, the tracemaker corrected them locally, indicating advanced ca¬ pabilities in orientation and odometry. These cognitive skills are compatible (though not exclusive) with the sophisticated navigation skills of the arthropod brain. The first appearance of Paleodictyon in the early Cambrian coincides with the earliest fossil record of arthropods, further supporting the hypothesis. Although environ¬ mental distribution and inferred function provide less definitive evidence, they do not exclude arthropod tracemakers. Taken together, these observations suggest that arthropods are the most likely producers of Pale¬ odictyon, challenging the hypotheses of a vermiform or protist producer. Isopods and amphipods emerge as the best potential candidates for producing Paleodictyon. However, only direct neoichnological observation of burrow construction, or the discovery of a tracemaker preserved within a fossil burrow, can definitively resolve the enduring mystery of its tracemaker. Wed, 30 Sep 2026 23:00:00 GMT http://hdl.handle.net/10174/42537 2026-09-30T23:00:00Z http://hdl.handle.net/10174/42534 Title: In Memoriam Luís Lopes (1964-2026) Authors: Moreira, Noel; Martins, Ruben; Peres, Marta; Frazão, Joana; Sousa, Mónica; Kullberg, José Carlos; Álvarez Areces, Enrique Abstract: In Memoriam Luís Lopes (1964-2026) Tue, 30 Jun 2026 23:00:00 GMT http://hdl.handle.net/10174/42534 2026-06-30T23:00:00Z http://hdl.handle.net/10174/42222 Title: Physical-Mechanical Changes in Portuguese, Greek, and Italian Marbles Under Aging Cycles Simulating Environmental Effects Linked to Bowing Authors: Pires, Vera; Sitzia, Fabio; Dias, Luis; Mirao, Jose; Neves, Samuel Abstract: Bowing, a significant form of decay, poses a crucial chal- lenge in the preservation of historical and contempo- rary structures, requiring comprehensive study and anal- ysis. This research focuses on the mechanical alterations induced by aging cycles of temperature and moisture on three distinct marbles (Portuguese, Greek, and Italian) emphasizing their susceptibility to bowing-associated effects. The prevalence of bowing in prominent histor- ical buildings underscores the urgency of understanding its underlying mechanisms and mitigating its impact. Through 50 aging cycles, this investigation discerns the distinct behaviors and properties exhibited by each marble, providing invaluable insights into the complex interac- tion between geological composition and environmental stressors. By highlighting the relevance of bowing and its detrimental effects on architectural heritage, this study underscores the importance of proactive measures in conservation and restoration efforts. Mon, 29 Sep 2025 23:00:00 GMT http://hdl.handle.net/10174/42222 2025-09-29T23:00:00Z http://hdl.handle.net/10174/42221 Title: Trentepohlia Algae as a Diagnostic Tool for Historic Mediterranean—Style Houses Authors: Sitzia, Fabio; Pires, Vera; Lisci, Carla; Neves, Samuel; Mirao, Josè Abstract: Trentepohlia is a genus of filamentous chlorophytes green algae commonly found in association with fungi and bacteria on building envelopes. Their colonies have a char- acteristic red coloration which results from the produc- tion of β-carotene and hematochrome pigments. They are commonly present on walls, roofs and other external building structures and thrive in humid and shaded envi- ronments where sufficient moisture is available. Since their growth is strongly influenced by factors such as water availability, time of wetness, substrate temperature, and lighting conditions, the distribution is usually non-uniform and reflects the varying moisture exposure across different parts of a building. Usually, Trentepohlia prevails in areas affected by water rebound, runoff, splashing, capillary rising or accidental water leaks. Moreover, Trentepohlia spotlights intervention restorations done by materials with different thermal conductivity and hygroscopic proper- ties. Given that water is one of the most damaging factors affecting building performance, these algae can serve as valuable bioindicators for detecting the most moisture-affected areas. In this work many case studies regarding tracer properties of Trentepohlia algae will be shown in association with building’s 3D reconstruction, Building Information Modeling, thermal imaging survey and chemical-physical analysis of the growing substrates. Mon, 29 Sep 2025 23:00:00 GMT http://hdl.handle.net/10174/42221 2025-09-29T23:00:00Z