scholarly journals Exploring abnormal Cambrian-aged trilobites in the Smithsonian collection

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8453 ◽  
Author(s):  
Russell D.C. Bicknell ◽  
Stephen Pates
Keyword(s):  
Natural History ◽  
Environmental Conditions ◽  
Injury Pattern ◽  
National Museum ◽  
Complete Understanding ◽  
Root Cause ◽  
Natural History Collection ◽  
Cambrian Trilobite ◽  
Predator Preference ◽  
Prey Items

Biomineralised trilobite exoskeletons provide a 250 million year record of abnormalities in one of the most diverse arthropod groups in history. One type of abnormality—repaired injuries—have allowed palaeobiologists to document records of Paleozoic predation, accidental damage, and complications in moulting experienced by the group. Although Cambrian trilobite injuries are fairly well documented, the illustration of new injured specimens will produce a more complete understanding of Cambrian prey items. To align with this perspective, nine new abnormal specimens displaying healed injuries from the Smithsonian National Museum of Natural History collection are documented. The injury pattern conforms to the suggestion of lateralised prey defence or predator preference, but it is highlighted that the root cause for such patterns is obscured by the lumping of data across different palaeoecological and environmental conditions. Further studies of Cambrian trilobites with injuries represent a key direction for uncovering evidence for the Cambrian escalation event.

Spend time now, save time later: IPM lessons learned from the National Museum of Natural History, Smithsonian Institution

2015 ◽  
Vol 29 (1-2) ◽  
pp. 61-66
Author(s):  
Amanda N. Lawrence ◽  
Jennifer Strotman
Keyword(s):  
Natural History ◽  
Pest Management ◽  
Smithsonian Institution ◽  
Lessons Learned ◽  
National Museum ◽  
Pest Infestation ◽  
Knowing That ◽  
Natural History Collection ◽  
New Pest

Abstract A case study involving a comprehensive inspection to discriminate between old and active pest infestations is described. Integrated pest management (IPM) processes within the National Museum of Natural History (NMNH), Smithsonian Institution, Division of Mammals (DOM) are challenging because of the size and composition of the collection, the age of storage equipment, and a low staffing to specimen ratio. Each specimen cabinet was inspected by IPM technicians during a 6-week period in late 2012. Following that inspection, two members of the NMNH collections program technician team began a 9-week project to clean 5,925 incidents in the affected cabinets in DOM storage areas in the Natural History Building downtown. The results of this project show that cleaning up a pest infestation in any natural history collection can be done in a reasonable amount of time and will help ensure the preservation of collections in the future. Knowing that the collections have been fully inspected and cleaned will allow staff in the DOM to easily and rapidly address future IPM issues in a structured way. Such efforts facilitate future IPM inspections because evidence of any new pest activity is no longer at risk of being overlooked due to debris from past infestations.

The palaeontological collection stored in the Department of Geology of the National Museum of Natural History NAS of Ukraine as a scientific heritage

Geo&Bio ◽  
2019 ◽  
Vol 2019 (17) ◽  
pp. 136-147
Author(s):  
Galina Anfimova ◽  
◽  
Volodymyr Grytsenko ◽  
Kateryna Derevska ◽  
Kseniia Rudenko ◽  
...  
Keyword(s):  
Natural History ◽  
National Museum ◽  
Scientific Heritage

Fin Level Defect Isolation Inside a FinFET Using Electron Beam Alteration of Current Flow

2017 ◽  
Author(s):  
H.J. Ryu ◽  
A.B. Shah ◽  
Y. Wang ◽  
W.-H. Chuang ◽  
T. Tong
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Focused Ion Beam ◽  
Current Flow ◽  
Ion Beam ◽  
The Body ◽  
Complete Understanding ◽  
Root Cause ◽  
Transmission Electron ◽  
Defect Isolation

Abstract When failure analysis is performed on a circuit composed of FinFETs, the degree of defect isolation, in some cases, requires isolation to the fin level inside the problematic FinFET for complete understanding of root cause. This work shows successful application of electron beam alteration of current flow combined with nanoprobing for precise isolation of a defect down to fin level. To understand the mechanism of the leakage, transmission electron microscopy (TEM) slice was made along the leaky drain contact (perpendicular to fin direction) by focused ion beam thinning and lift-out. TEM image shows contact and fin. Stacking fault was found in the body of the silicon fin highlighted by the technique described in this paper.

Ocotea dilcherii, a new name for Ocotea obtusifolia (Berry) LaMotte (Lauraceae)

Phytotaxa ◽  
2015 ◽  
Vol 239 (2) ◽  
pp. 199
Author(s):  
Sergei Vasilyevich Vikulin
Keyword(s):  
Natural History ◽  
Type Specimen ◽  
Valid Species ◽  
Early Eocene ◽  
National Museum ◽  
Mississippi Embayment ◽  
Fossil Species ◽  
Early Oligocene ◽  
Leaf Remains ◽  
Nomen Novum

The fossil species  Oreodaphne obtusifolia Berry (1916: 301) was described, based on the fossil leaf remains of the most abundant laurel from the Early Eocene Wilcox Group sediments of Holly Springs: Marshall Co, Grenada Co., Miss.: Mississippi embayment (Southeastern North America). Nowadays, most systematists consider the extant Oreodaphne to be a member of Ocotea (Mez, 1889: 219; Rohwer, 1986; van der Werff, 2002; Chanderbali et al., 2001). LaMotte (1952) transferred Berry’s (1916: 301) combination to Ocotea, and this transfer was followed by Dilcher (1963), who reinforced attribution of Wilcox leaf megafossils to Ocotea by cuticular analysis of epidermis and stomata (Dilcher & Lott, 2005). However, according to Art. 53.1 of the ICN (McNeill et al.  2012) the name Ocotea obtusifolia (Berry) LaMotte (1952) is illegitimate because of the existence of the earlier overlooked homonym, Ocotea obtusifolia Kunth (1817: 165–166), an extant lauraceous species from Colombia (Muséum National d’Histoire Naturelle, holotype: http://plants.jstor.org/stable/10.5555/al.ap.specimen.P00128771). The homonymy between these fossil and extant American species of Ocotea was revealed during the description of the new fossil Early Oligocene species Ocotea rossica Vikulin from the south of the Middle-Russian upland (Vikulin, 2015: 326). Since Ocotea obtusifolia (Berry) LaMotte has been systematically recognized as a valid species in current use and it does not have any synonym, a nomen novum, O. dilcherii, is formally proposed here as a replaced name. Because a type specimen was not indicated among the validating illustrations of Berry (1916: pl. 80, fig. 1; pl. 83, fig. 2–5, and pl. 84, fig. 1 and 2), a lectotype must be designated here, from the specimens illustrated in the protologue (Berry, 1916: 301–302) amongst those perfect specimens with blunt leaf apex, which are very abundant in the clays at Puryear, Tenn. (Proposed lectotype: paleobotany collection # USNM 35867, Smithsonian National Museum of Natural History (USA), illustrated in Berry, 1916: 301, pl. 83, fig. 5.

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