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opencc-by-4.0Sep 2020View details →

Greenland Peregrine Falcon eggshell thickness monitoring data 1972 - 2019

The Peregrine Falcon (Falco peregrinus tundrius) population in Greenland has been monitored in different survey areas in South and West Greenland since 1972. At visits to Peregrine Falcon nests, eggshell fragments from hatched eggs as well as addled (dead) eggs left behind have been collected with the aim of monitoring the thickness of the eggshells as well as analysing the whole eggs for contaminants. The shell thickness serves as a proxy for the falcons’ exposure to certain persistant organic pollutants, in particular DDT and its breakdown products (see summaries in Cade et al. 1988). This data set contains the raw data on 6665 eggshell thickness measurements of: 1.    Whole eggs from South Greenland 1986-2015 2.    Eggshell fragments from the study area in South Greenland 1981-2019 3.    Eggshell fragments from the study area around Kangerlussuaq in West Greenland 1972-1989 The data set contains a mix of measurements of shell thickness including or excluding the eggshell membranes from the same clutch of eggs. Based on those measurements the average membrane thickness is 0.071 mm (SD=0.013) – a figure confirmed by other studies – and this ’membrane factor’ can be added or subtracted for comparisons with other data sets. Further details regarding the sampling areas, measurement methods and the results of trends analyses of changes in shell thickness are provided in Falk et al. (2006 and 2018). The file named 1_Data_Eggshell_Thickness_1972-2019.csv contains the raw measurements data and the file 2_ReadMe_Eggshell_Thickness_1972-2019.txt specifies the content.  The file named 3_Rscript_Eggshell_Thickness_1972-2019.R provides an R script for summarizing and plotting the data as shown in the file 4_Plot_Eggshell_Thickness_1972-2019.pdf

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Eggshell colour differences in a classic example of coevolved eggshell mimicry

Avian brood parasitism is a model system for understanding coevolutionary arms races, and the great reed warbler (Acrocephalus arundinaceus, hereafter 'warbler') and its parasite the common cuckoo (Cuculus canorus, hereafter 'cuckoo') are prime examples of this coevolutionary struggle. Here, warblers select for egg colour mimicry by rejecting poorly matched cuckoo eggs. Contrary to long-held assumptions, recent work showed that warblers tend to reject lighter and browner eggs but tended to accept darker and bluer eggs rather than basing rejection decisions solely on perceived colour differences (i.e., the degree of mimicry). This counter-intuitive, colour-biased rejection behaviour would select for bluer and darker cuckoo eggs, but would only be adaptive if cuckoos were consistently lighter and browner than warbler eggs. Therefore, we tested whether warbler eggs were consistently bluer and darker than the cuckoo eggs. To do so, we re-analysed eggshell reflectance spectra of warblers and the cuckoos that parasitized them in the Czech Republic. As expected, we found that warbler eggs were significantly bluer and darker than the cuckoo eggs at the population level. Thus, we demonstrate imperfect mimicry in a long-coevolved cuckoo host-race and provide insights for exploring the coevolutionary interactions among hosts and their brood parasites.

opencc-zeroNov 2023View details →

Fig. 3 in An Investigation Of Embryo And Eggshell Development In Trichuris Suis (Nematoda, Trichuridae0 Under Laboratory Conditions

Fig. 3. Eggs of Trichuris suis at bean-like embryo stage of development: а — sampled from nematode gonads, 25th day of cultivation (×400); b — sampled from faeces of infected pigs, 20th day of cultivation (×450).

Fig. 5 in An Investigation Of Embryo And Eggshell Development In Trichuris Suis (Nematoda, Trichuridae0 Under Laboratory Conditions

Fig. 5. Infectious Trichuris suis egg: а — sampled from nematode gonads, 40th day of cultivation (×350); b — sampled from faeces of infected pigs, 30th day of cultivation (×450).

Fig. 1 in An Investigation Of Embryo And Eggshell Development In Trichuris Suis (Nematoda, Trichuridae0 Under Laboratory Conditions

Fig. 1. Eggs of Trichuris suis at the protoplast stage of development: a — sampled from nematode gonads: 1 — unformed, 2 — formed (×350); b — sampled from faeces of sick pigs (×450).

Fig. 2 in An Investigation Of Embryo And Eggshell Development In Trichuris Suis (Nematoda, Trichuridae0 Under Laboratory Conditions

Fig. 2. Eggs of Trichuris suis at blastomere cleavage stage of development: а — sampled from nematode gonads, 15th day of cultivation (×400); b — sampled from faeces of infected pigs, 10th day of cultivation (×500).

Fig. 4 in An Investigation Of Embryo And Eggshell Development In Trichuris Suis (Nematoda, Trichuridae0 Under Laboratory Conditions

Fig. 4. Eggs of Trichuris suis at the stage of developing larvae: а — sampled from nematode gonads, 30th day of cultivation (×300); b — sampled from faeces of infected pigs, 20th day of cultivation (×450).

opencc-zeroNov 2019View details →

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Data from: Comparative crystallography suggests Maniraptoran theropod affinities for latest cretaceous European 'geckoid' eggshell

Thin fossil eggshells from Upper Cretaceous deposits of Europe, characterized by nodular ornamentation similar to modern gekkotan eggshells, have mostly been interpreted as gekkotan (='geckoid') in origin. However, in some cases, like the oogenus Pseudogeckoolithus, their theropod affinity was also suggested. The true affinity of these fossil 'geckoid' eggshells remained controversial due to the absence of analytical methods effective in identifying genuine gecko eggshells in the fossil record. In this study, we apply electron backscatter diffraction (EBSD) analysis to latest Cretaceous European 'geckoid' (including Pseudogeckoolithus) eggshells, in comparison with modern gekkotan and theropod (avian) eggshells. Our results show that Pseudogeckoolithus has a definite theropod eggshell-like crystallographic configuration, in clear contrast to that seen in modern geckos. Furthermore, the crystallography of the nodular ornamentation in Pseudogeckoolithus is comparable to that seen in megapode eggshells, but different from that of gecko eggshells, despite superficial morphological similarity. The remarkable morphological similarities between Pseudogeckoolithus and modern gecko eggshells are thus convergent, and the 'gekkotan affinity' hypothesis can be dismissed for Pseudogeckoolithus. This study provides a template for differentiating true gekkotan from dinosaurian eggshells in the fossil record. The potential functional significance of eggshell ornamentation, lost in most modern birds, requires further study, and experimental zoological approach may shed light on this issue. Finally, our results caution about the dangers of using potentially homoplastic eggshell characters in eggshell parataxonomy.

opencc-by-4.0Jul 2024View details →

Рис. 1. Схема точек отбора проб на ООПТ в бассейне Амура Fig. 1. Map of sampling points at the protected areas in the Amur River Basin in Molting feathers and eggshells in monitoring rare bird species populations: Evidence from special protected natural territories

Рис. 1. Схема точек отбора проб на ООПТ в бассейне Амура Fig. 1. Map of sampling points at the protected areas in the Amur River Basin

opencc-by-4.0Jul 2024View details →

Рис. 3. Соотношение концентраций биогенных микроэΛементов в очинах перьев (а) и скорΛупе яиц аистов (b), мг/кг Fig. 3. Concentratiom ratio of biogenic trace elements in the edges of feathers (a) and eggshells (b) of storks, mg/kg in Molting feathers and eggshells in monitoring rare bird species populations: Evidence from special protected natural territories

Рис. 3. Соотношение концентраций биогенных микроэΛементов в очинах перьев (а) и скорΛупе яиц аистов (b), мг/кг Fig. 3. Concentratiom ratio of biogenic trace elements in the edges of feathers (a) and eggshells (b) of storks, mg/kg

Fig. 4 in Unusual theropod eggshells from the Early Cretaceous Blesa Formation of the Iberian Range, Spain

Fig. 4. Variations in outer surface ornamentation of prismatoolithid therapod eggshell Trigonoolithus amoae oogen. et oosp. nov. from La Cantalera 1 site, Early Barremian. Eggshells showing triangular (A–C) and rounded ornamentation (D–F). Pristine eggshells showing well-preserved ornamentation (A, D). Lightly eroded eggshells showing degradation (B, E). Eroded eggshells showing coalescence of triangles (C, F). A. MPZ 2012/740. B. MPZ 2012/742. C. MPZ 2012/743. D. MPZ 2012/731. E. MPZ 2012/729. F. MPZ 2012/728. Scale bar 1000 μm.

Fig. 5 in Unusual theropod eggshells from the Early Cretaceous Blesa Formation of the Iberian Range, Spain

Fig. 5. Strict consensus trees showing the hypothesized phylogenetic position of Trigonoolithus amoe oogen. et oosp. nov. from La Cantalera 1 site, Early Barremian. A. Matrix of Varricchio and Jackson (2004). Strict consensus of six equally parsimonious trees of 38 steps was recovered (C.I. 0.737; R.I. 0.853; R.C. 0.629). B. Matrix of Grellet-Tinner and Makovicky (2006). Strict consensus tree of three equally most parsimonious trees of 36 steps (C.I. 0.750; R.I. 0.852; R.C. 0.639). C. Matrix of Zelenitsky and Therrien (2008b). Most parsimonious tree of 18 steps (C.I. 1.000; R.I. 1.000; R.C.1.000). D. LópezMartínez and Vicens (2012) version of the dataset: a new analysis of Prismatoolithidae using the matrix of Zelenitsky and Therrien (2008) and adding the new oogenus Sankofa and the Patagonian eggs of Bajo de la Carpa (Schweitzer et al. 2002). Strict consensus of seven equally parsimonious trees of 19 steps (C.I. 0.947; R.I. 0.958; R.C. 0.907). All trees show Trigonoolithus placed in polytomy or at the base of the "Prismatoolithidae+avian eggs" clade.

Fig. 1 in Unusual theropod eggshells from the Early Cretaceous Blesa Formation of the Iberian Range, Spain

Fig. 1. Geographical and geological location of the site of La Cantalera 1 (early Barremian, Teruel, Spain), modified from Canudo et al. (2010). A. Simplified geological map of the Iberian Peninsula. B. Palaeogeographic subbasins (Ol, Oliete; Pa, Las Parras; Ga, Galve; Mo, Morella; Pe, Perelló; Sa, Salzedella; Pg, Peñagolosa) within the Maestrazgo Basin and active faults during Early Cretaceous sedimentation, modified from Salas et al. (2001). C. Detailed location of the La Cantalera site near the village of Josa, Teruel. D. Geological map of the La Cantalera area with the local geological units.

Fig. 3 in Unusual theropod eggshells from the Early Cretaceous Blesa Formation of the Iberian Range, Spain

Fig. 3. Thin-sections of prismatoolithid therapod eggshell Trigonoolithus amoae oogen. et oosp. nov. from La Cantalera 1 site, Early Barremian. A. MPZ 2012/856, light microphotograph. B. MPZ 2012/862, light microphotograph (B 1), microphotograph showing eggshell under cross-polars (B 2). C. MPZ2012/850, cathodoluminescence image showing dark blue luminescence except for some orange tones in the mammillary layer, probably due to the high amount of organic matter in this area. Scale bars 500 μm.

FIGURE 9 in Identification of fossilized eggshells from the Taung hominin locality, Taung, Northwest Province, South Afric

FIGURE 9. Cross-plot of oxygen and carbon isotope values from fossil eggshells and sediment, base of the Dart Pinnacle, Taung. There is a high degree of consistency between replicate samples, and each eggshell fragment shows a distinct isotopic signature, indicating that the eggshells are derived from different individuals (with the possible exception of TDES 2 & TDES 3). The δ13C values indicate that all eggshells have a predominantly C4 (savannah grass) dietary signal, with the exception of T93-17 which has a pure (or almost pure) C3 diet.

FIGURE 4 in Identification of fossilized eggshells from the Taung hominin locality, Taung, Northwest Province, South Afric

FIGURE 4. All specimens, both extant eggs and fossil eggshells, showing surface morphology at 57X magnification.

FIGURE 5 in Identification of fossilized eggshells from the Taung hominin locality, Taung, Northwest Province, South Afric

FIGURE 5. Renderings of fossil eggshell fragments embedded in matrix (1-2) and indication of the internal boundary between eggshell and matrix (3-4). Images 1 and 3 are fossil eggshell fragment T92-88, and images 2 and 4 are fossil eggshell fragment T93-17. Note the relatively consistent thickness at the edges and how this maintained surface curvatures indicated by the external surfaces.

FIGURE 6. Fossil eggshell fragments T92-88 in Identification of fossilized eggshells from the Taung hominin locality, Taung, Northwest Province, South Afric

FIGURE 6. Fossil eggshell fragments T92-88 (blue) and T93-17 (yellow) fit to eggs from five extant birds. Fits depicted visually in the figure (rigidly constrained size) correspond to root mean square (RMS) values reported in Table 2. Note that visual correspondence supports quantification of RMS values in that fossil eggshell fragment T92-88 fits best with the blunt pole of the extant guinea fowl egg. Extant black eagle (blunt pole) and giant eagle owl (apical pole) eggs provide the next closest, but still worse fits. Fossil eggshell fragment T93-17 fits best with the equatorial region of the black eagle egg. The extant guinea fowl egg provides the next closest fit for fossil eggshell fragment T93-17.

FIGURE 8 in Identification of fossilized eggshells from the Taung hominin locality, Taung, Northwest Province, South Afric

FIGURE 8. (1) Fossilized eggshell fragments T92-88 (blue) and T93-17 (yellow) indicating best fit to the same black eagle egg as illustrated in Figure 6, plus six additional black eagle eggs. Note despite intraspecific variability in egg shape, the fits are quite similar (also see Table 3). This suggests even accounting for intraspecific variability in egg shape Results in Table 2 should be robust. (2) Fossil eggshell fragments T92-88 (blue) and T93-17 (yellow) indicating best fit to the same guinea fowl egg as illustrated in Figure 6 (far left), plus four additional guinea fowl eggs. Note that despite intraspecific variability in egg shape, the fits are quite consistent (also see Table 3). This suggests that even accounting for intraspecific variability in egg shape results of the surface curvature analyses are robust.

FIGURE 2 in Identification of fossilized eggshells from the Taung hominin locality, Taung, Northwest Province, South Afric

FIGURE 2. All specimens, both extant eggs and fossil eggshells, showing surface morphology at 6.3X magnification.