Pub Date : 2023-01-02DOI: 10.1080/10420940.2023.2204231
Charles W. Helm, A. Carr, M. Lockley, H. Cawthra, Jan C. de Vynck, M. Dixon, W. Stear, Guy H. H. Thesen
Abstract Seven hominin ichnosites in aeolianites on the Cape south coast of South Africa have been dated using Optically Stimulated Luminescence, yielding age estimates from Marine Isotope 6 through Marine Isotope Stage 4. All rock outcrops containing these sites are situated on the modern coastline. The new ages are consistent with geomorphological expectations, and with other numerical dating results from the wider southern Cape coastline. Seen in a global ichnological context, the cluster of South African sites (including two previously dated sites) contains nine of the twenty-three sites older than 70 ka from which hominin tracks have been reported. With a single exception they are also the only sites older than 40 ka that have been attributed to Homo sapiens, and include the oldest tracks (153 ± 10 ka) thus far attributed to our species. The South African coastline contains an archaeological and palaeoanthropological record of global significance, to which the hominin ichnological record, preserved on aeolianite palaeosurfaces and now chronologically constrained, can make a substantial contribution.
{"title":"Dating the Pleistocene hominin ichnosites on South Africa’s Cape south coast","authors":"Charles W. Helm, A. Carr, M. Lockley, H. Cawthra, Jan C. de Vynck, M. Dixon, W. Stear, Guy H. H. Thesen","doi":"10.1080/10420940.2023.2204231","DOIUrl":"https://doi.org/10.1080/10420940.2023.2204231","url":null,"abstract":"Abstract Seven hominin ichnosites in aeolianites on the Cape south coast of South Africa have been dated using Optically Stimulated Luminescence, yielding age estimates from Marine Isotope 6 through Marine Isotope Stage 4. All rock outcrops containing these sites are situated on the modern coastline. The new ages are consistent with geomorphological expectations, and with other numerical dating results from the wider southern Cape coastline. Seen in a global ichnological context, the cluster of South African sites (including two previously dated sites) contains nine of the twenty-three sites older than 70 ka from which hominin tracks have been reported. With a single exception they are also the only sites older than 40 ka that have been attributed to Homo sapiens, and include the oldest tracks (153 ± 10 ka) thus far attributed to our species. The South African coastline contains an archaeological and palaeoanthropological record of global significance, to which the hominin ichnological record, preserved on aeolianite palaeosurfaces and now chronologically constrained, can make a substantial contribution.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"84 1","pages":"49 - 68"},"PeriodicalIF":0.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86207573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/10420940.2023.2187387
M. Bendella, A. Hunt, M. Benyoucef, Imad Bouchemla
Abstract Nine morphotypes of coprolites, including Heteropolacopros texaniensis, Liassocopros isp., Hyronocopros amphipola, Eucoprus isp. 1, Eucoprus isp. 2, Morphotype 1, Morphotype 2, Morphotype 3, and Morphotype 4, are distinguished from the basal Late Cretaceous (Lower Cenomanian) of the ‘Continental Intercalaire’ deposits at Gara Samani (Sahara, southern Algeria). This coprofauna is the first to be identified, described and illustrated from the Mesozoic of Algeria. It adds new information on the trace-fossil assemblages previously reported from the Cretaceous localities of North Africa. The Gara Samani coproassociation marks the youngest occurrence of the ichnogenera Heteropolacopros and Hyronocopros. Most coprolites were produced by ichthyophagous carnivores, such as crocodiles, theropods (Spinosaurus) and different kinds of fish.
{"title":"The first Mesozoic vertebrate coprolites from Algeria","authors":"M. Bendella, A. Hunt, M. Benyoucef, Imad Bouchemla","doi":"10.1080/10420940.2023.2187387","DOIUrl":"https://doi.org/10.1080/10420940.2023.2187387","url":null,"abstract":"Abstract Nine morphotypes of coprolites, including Heteropolacopros texaniensis, Liassocopros isp., Hyronocopros amphipola, Eucoprus isp. 1, Eucoprus isp. 2, Morphotype 1, Morphotype 2, Morphotype 3, and Morphotype 4, are distinguished from the basal Late Cretaceous (Lower Cenomanian) of the ‘Continental Intercalaire’ deposits at Gara Samani (Sahara, southern Algeria). This coprofauna is the first to be identified, described and illustrated from the Mesozoic of Algeria. It adds new information on the trace-fossil assemblages previously reported from the Cretaceous localities of North Africa. The Gara Samani coproassociation marks the youngest occurrence of the ichnogenera Heteropolacopros and Hyronocopros. Most coprolites were produced by ichthyophagous carnivores, such as crocodiles, theropods (Spinosaurus) and different kinds of fish.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"21 1","pages":"27 - 38"},"PeriodicalIF":0.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89699687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-29DOI: 10.1080/10420940.2022.2138378
J. Zonneveld
{"title":"On the status of the ichnotaxon Mandaodonites coxii Cruickshank, 1986","authors":"J. Zonneveld","doi":"10.1080/10420940.2022.2138378","DOIUrl":"https://doi.org/10.1080/10420940.2022.2138378","url":null,"abstract":"","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"16 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84534277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182301
V. Šimo, B. Zahradníková
Abstract A new find of one specimen of the relatively rare trace fossil Radhostium carpaticum is the subject of this morphological study. The new find from the Biele Karpaty Unit, is preserved on the soles of turbiditic sandstones within the Upper Cretaceous and Eocene turbiditic sequence of the Svodnice Formation in the Biele Karpaty Mountains, Slovakia. The morphological study of the trace fossil is based on this and the available published individuals of Radhostium. The burrow reveals a regular morphological system consisting of cylindrical U-shaped shafts (elements) arranged in a row linked by a horizontal burrow. Morphology shows that the trace fossil most likely corresponds to an open burrow system of domichnion without back fill. This morphology indicates that it is essentially a branched burrow and does not represent the chevron structure typical for trace fossils of molluscs. However, this morphology is comparable to no known form, so the producer of the trace fossil cannot be reliably determined. Referred ichnospecies of Radhostium have been recorded in three geographic regions (Alps, Carpathians, Apennines). All specimens of R. carpaticum occur in Upper Cretaceous and Palaeocene turbiditic deep-marine sequences. Thus, Radhostium occurs within a relatively narrow stratigraphic range in interconnected palaeogeographic areas in the Western Tethys.
{"title":"Morphology of Radhostium carpaticum Plička and Říha, 1989 in new finds from the Outer Western Carpathians (Upper Cretaceous – Eocene flysch deposits of the Biele Karpaty Mountains, Slovakia)","authors":"V. Šimo, B. Zahradníková","doi":"10.1080/10420940.2023.2182301","DOIUrl":"https://doi.org/10.1080/10420940.2023.2182301","url":null,"abstract":"Abstract A new find of one specimen of the relatively rare trace fossil Radhostium carpaticum is the subject of this morphological study. The new find from the Biele Karpaty Unit, is preserved on the soles of turbiditic sandstones within the Upper Cretaceous and Eocene turbiditic sequence of the Svodnice Formation in the Biele Karpaty Mountains, Slovakia. The morphological study of the trace fossil is based on this and the available published individuals of Radhostium. The burrow reveals a regular morphological system consisting of cylindrical U-shaped shafts (elements) arranged in a row linked by a horizontal burrow. Morphology shows that the trace fossil most likely corresponds to an open burrow system of domichnion without back fill. This morphology indicates that it is essentially a branched burrow and does not represent the chevron structure typical for trace fossils of molluscs. However, this morphology is comparable to no known form, so the producer of the trace fossil cannot be reliably determined. Referred ichnospecies of Radhostium have been recorded in three geographic regions (Alps, Carpathians, Apennines). All specimens of R. carpaticum occur in Upper Cretaceous and Palaeocene turbiditic deep-marine sequences. Thus, Radhostium occurs within a relatively narrow stratigraphic range in interconnected palaeogeographic areas in the Western Tethys.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"104 1","pages":"137 - 147"},"PeriodicalIF":0.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85381672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182297
Abhijit Chakraborty, S. Mandal, Sreepat Jain
Abstract Plant–animal interactions investigated largely in Glossopteris leaf fossils (1214 specimens) from the lower Permian strata of peninsular India reveal evidence of taphonomic modifications of the ichnofabric. The leaf fossils indicate both above-ground (pre-depositional) and on-ground (post-depositional) animal activities. Animal traces that extend beyond the margins of the leaf compressions or are emplaced on the leaf impressions are evidently post-depositional, preserved ex situ. Both feeding (herbivory/detritivory) and locomotary animal traces are interpreted in the host media. Preserved traces in the leaf fossils depict arrays of pre- and post-depositional events (viz., biotic interactions on green foliage, leaf detachment from the trees, post-mortem transport and burial) along taphonomic pathways. Accordingly, five taphonomic pathways are proposed based on varied combinations of pre- and post-depositional traces, emplaced on leaf fossils. Low diversity and persistent rarity of post-depositional traces (4%) as compared to more common pre-depositional traces (7%) in the sample population are noted. Less common post-depositional trace fossil assemblages of depauperate diversity indicate that stressed habitats prevailed at the depositional sites and a limited time window for preservation of plant–animal interactions. The recognition of pre- and post-depositional trace fossil suites ensures ichnological and ethological fidelity of faunal data on plant–animal interactions.
{"title":"Taphonomic overprinting on the late Palaeozoic terrestrial plant–animal interactions: a noise in the record","authors":"Abhijit Chakraborty, S. Mandal, Sreepat Jain","doi":"10.1080/10420940.2023.2182297","DOIUrl":"https://doi.org/10.1080/10420940.2023.2182297","url":null,"abstract":"Abstract Plant–animal interactions investigated largely in Glossopteris leaf fossils (1214 specimens) from the lower Permian strata of peninsular India reveal evidence of taphonomic modifications of the ichnofabric. The leaf fossils indicate both above-ground (pre-depositional) and on-ground (post-depositional) animal activities. Animal traces that extend beyond the margins of the leaf compressions or are emplaced on the leaf impressions are evidently post-depositional, preserved ex situ. Both feeding (herbivory/detritivory) and locomotary animal traces are interpreted in the host media. Preserved traces in the leaf fossils depict arrays of pre- and post-depositional events (viz., biotic interactions on green foliage, leaf detachment from the trees, post-mortem transport and burial) along taphonomic pathways. Accordingly, five taphonomic pathways are proposed based on varied combinations of pre- and post-depositional traces, emplaced on leaf fossils. Low diversity and persistent rarity of post-depositional traces (4%) as compared to more common pre-depositional traces (7%) in the sample population are noted. Less common post-depositional trace fossil assemblages of depauperate diversity indicate that stressed habitats prevailed at the depositional sites and a limited time window for preservation of plant–animal interactions. The recognition of pre- and post-depositional trace fossil suites ensures ichnological and ethological fidelity of faunal data on plant–animal interactions.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"70 1","pages":"166 - 184"},"PeriodicalIF":0.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77924809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182300
Adam Lindholm, S. J. Godfrey, L. Ward, A. Collareta
Abstract Vertebrate-bitten coprolites are seemingly rare; nonetheless, within the past dozen years, a handful of these composite trace fossils have been found and described. Here, we describe a single crocodile coprolite from the Lower Miocene Calvert Formation in New Kent County, Virginia, USA, showing bite marks. The size and morphology of the coprolite is consistent with a crocodilian origin. Seven parallel, gently curving gouges, of biogenic origin, disrupt the surface of the coprolite. As it is a medium preserving bite marks, this coprolite qualifies as a morderolite. Furthermore, because of the presence of larger/deeper primary, and finer secondary gouges, which we interpreted as individual tooth marks, the identity of the vertebrate that bit the coprolite is most likely gar (Lepisosteidae). Because other comparable coprolites preserving similar sets of primary and secondary gouges are known, this unique trace fossil is given a new ichnotaxonomic name, Machichnus dimorphodon isp. nov. Many more much smaller markings, interpreted as feeding traces by smaller organisms (possibly invertebrates) also ornament the surface of the coprolite.
{"title":"A gar-bitten vertebrate coprolite from the Neogene of the Atlantic Coastal Plain, USA, and a new ichnospecies of Machichnus Mikuláš et al., 2006","authors":"Adam Lindholm, S. J. Godfrey, L. Ward, A. Collareta","doi":"10.1080/10420940.2023.2182300","DOIUrl":"https://doi.org/10.1080/10420940.2023.2182300","url":null,"abstract":"Abstract Vertebrate-bitten coprolites are seemingly rare; nonetheless, within the past dozen years, a handful of these composite trace fossils have been found and described. Here, we describe a single crocodile coprolite from the Lower Miocene Calvert Formation in New Kent County, Virginia, USA, showing bite marks. The size and morphology of the coprolite is consistent with a crocodilian origin. Seven parallel, gently curving gouges, of biogenic origin, disrupt the surface of the coprolite. As it is a medium preserving bite marks, this coprolite qualifies as a morderolite. Furthermore, because of the presence of larger/deeper primary, and finer secondary gouges, which we interpreted as individual tooth marks, the identity of the vertebrate that bit the coprolite is most likely gar (Lepisosteidae). Because other comparable coprolites preserving similar sets of primary and secondary gouges are known, this unique trace fossil is given a new ichnotaxonomic name, Machichnus dimorphodon isp. nov. Many more much smaller markings, interpreted as feeding traces by smaller organisms (possibly invertebrates) also ornament the surface of the coprolite.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"5 1","pages":"185 - 194"},"PeriodicalIF":0.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87170759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182298
Harry M. Maisch, Martin A Becker
Abstract Partially carbonized driftwood recovered from a lag deposit at the Arkadelphia Formation–Midway Group Contact (K–Pg) near Malvern, Arkansas contains an abundance of macrobioerosion. Macroborings are oriented perpendicular and oblique to the wood grain, straight to sinuous in shape, ≤8 cm long, may have calcitic linings, and belong to Teredolites clavatus (Kelly & Bromley, 1984). The abundance and tightly spaced position of borings on all driftwood surfaces suggests the wood was afloat and/or exposed on or near the seafloor in a shallow marine setting for an extended period of time before becoming buried. Transverse, radial, and tangential thin section analysis of the driftwood identifies distinct growth rings, tracheid and ray cells, ray pits, and resin canals of the bald cypress genus, Taxodium. The presence of Taxodium wood in addition to a diverse and abundant assemblage of transitional to shallow marine vertebrates in the Gulf Coastal Plain of southwestern Arkansas indicate that brackish water swamps were in proximity to the ancestral shoreline around the K–Pg boundary and that these remains were concentrated into a lag deposit as the result of storm events, sea-level cyclicity, and possibly impact generated tsunamis.
{"title":"Teredolites driftwood from the Arkadelphia Formation–Midway Group Contact (K–Pg), Malvern, Arkansas, USA","authors":"Harry M. Maisch, Martin A Becker","doi":"10.1080/10420940.2023.2182298","DOIUrl":"https://doi.org/10.1080/10420940.2023.2182298","url":null,"abstract":"Abstract Partially carbonized driftwood recovered from a lag deposit at the Arkadelphia Formation–Midway Group Contact (K–Pg) near Malvern, Arkansas contains an abundance of macrobioerosion. Macroborings are oriented perpendicular and oblique to the wood grain, straight to sinuous in shape, ≤8 cm long, may have calcitic linings, and belong to Teredolites clavatus (Kelly & Bromley, 1984). The abundance and tightly spaced position of borings on all driftwood surfaces suggests the wood was afloat and/or exposed on or near the seafloor in a shallow marine setting for an extended period of time before becoming buried. Transverse, radial, and tangential thin section analysis of the driftwood identifies distinct growth rings, tracheid and ray cells, ray pits, and resin canals of the bald cypress genus, Taxodium. The presence of Taxodium wood in addition to a diverse and abundant assemblage of transitional to shallow marine vertebrates in the Gulf Coastal Plain of southwestern Arkansas indicate that brackish water swamps were in proximity to the ancestral shoreline around the K–Pg boundary and that these remains were concentrated into a lag deposit as the result of storm events, sea-level cyclicity, and possibly impact generated tsunamis.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"1 1","pages":"117 - 136"},"PeriodicalIF":0.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86693306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182296
Javier Ruiz, Federico Mansilla, J. Arsuaga, Elena Santos, A. Jiménez‐Díaz, I. Egea-González
Abstract Since their discovery in 1978, the hominin fossil footprints from Laetoli have been the focus, of extensive research on the locomotion, speed, body size, and behavior of the responsible track-makers (nominally Australopithecus afarensis). In this work, we show that careful examination of walking speed and displacement yields valuable information regarding the interaction between individuals, as well as group behavior of the track-maker hominins. First, we calculate statures for the Site G and S hominins using appropriate footprint length/stature ratios, obtaining statures ranging from 1.2 to 1.6 − 1.7 m. This range is somewhat taller than that proposed for Au. afarensis from skeletal remains (roughly 1.1 to 1.6 m), thus suggesting that comparatively large individuals are possibly represented in the Laetoli footprints. We then calculate speeds for the Site G track-makers from a stride length-speed scaling for humans. Stride and step lengths are measured from a digital model using the deepest point on the heel area of the G1 and G3 footprints as reference, and the deepest point on the hallux area for the overprinted G2 footprints. The hominins responsible for the Site G trackways all walked at a very similar mean speed, around 0.8 m s−1, which is faster than the speeds proposed by some previous studies. Detailed step-to-step speed calculations for G1 and G3 hominins show that the walking speed varied substantially (up to a factor of 1.5) over distances of just a few meters, perhaps due to surface conditions or behavioral reasons. The centers of mass of the G1 and G3 hominins traced very similar trajectories along the trackway portion examined. Thus, all Site G track-makers appear to have been moving together: the G1 and G3 hominins walked over the Laetoli ashes together in parallel, following behind the G2 hominin.
自1978年在Laetoli发现的古人类足迹化石以来，一直是人们对足迹制造者(名义上的南方古猿阿法种)的运动、速度、体型和行为进行广泛研究的焦点。在这项工作中，我们展示了对行走速度和位移的仔细检查，可以获得关于个体之间相互作用的有价值的信息，以及制造足迹的人类的群体行为。首先，我们使用合适的足迹长度/身高比计算了G和S遗址古人类的身高，得到了1.2至1.6 - 1.7 m的身高。这个范围比金的范围略高。阿法种的骨骼残骸(大约1.1到1.6米)，因此表明在Laetoli脚印中可能代表了相对较大的个体。然后，我们根据人类的跨步长度-速度缩放来计算Site G轨迹制造者的速度。步幅和步长是从数字模型中测量的，使用G1和G3脚印的鞋跟区域的最深点作为参考，以及套印G2脚印的拇趾区域的最深点作为参考。负责Site G轨道的古人类都以非常相似的平均速度行走，大约0.8 m s - 1，这比之前一些研究提出的速度要快。G1和G3古人类详细的步间速度计算表明，在仅仅几米的距离内，行走速度变化很大(高达1.5倍)，可能是由于地表条件或行为原因。G1和G3古人类的质心沿着被检查的轨道部分描画出非常相似的轨迹。因此，所有G遗址的足迹制造者似乎都是一起移动的:G1和G3古人类是平行走过莱托里灰烬的，G2古人类紧随其后。
{"title":"The speed and displacement of the Laetoli Site G track-maker hominins","authors":"Javier Ruiz, Federico Mansilla, J. Arsuaga, Elena Santos, A. Jiménez‐Díaz, I. Egea-González","doi":"10.1080/10420940.2023.2182296","DOIUrl":"https://doi.org/10.1080/10420940.2023.2182296","url":null,"abstract":"Abstract Since their discovery in 1978, the hominin fossil footprints from Laetoli have been the focus, of extensive research on the locomotion, speed, body size, and behavior of the responsible track-makers (nominally Australopithecus afarensis). In this work, we show that careful examination of walking speed and displacement yields valuable information regarding the interaction between individuals, as well as group behavior of the track-maker hominins. First, we calculate statures for the Site G and S hominins using appropriate footprint length/stature ratios, obtaining statures ranging from 1.2 to 1.6 − 1.7 m. This range is somewhat taller than that proposed for Au. afarensis from skeletal remains (roughly 1.1 to 1.6 m), thus suggesting that comparatively large individuals are possibly represented in the Laetoli footprints. We then calculate speeds for the Site G track-makers from a stride length-speed scaling for humans. Stride and step lengths are measured from a digital model using the deepest point on the heel area of the G1 and G3 footprints as reference, and the deepest point on the hallux area for the overprinted G2 footprints. The hominins responsible for the Site G trackways all walked at a very similar mean speed, around 0.8 m s−1, which is faster than the speeds proposed by some previous studies. Detailed step-to-step speed calculations for G1 and G3 hominins show that the walking speed varied substantially (up to a factor of 1.5) over distances of just a few meters, perhaps due to surface conditions or behavioral reasons. The centers of mass of the G1 and G3 hominins traced very similar trajectories along the trackway portion examined. Thus, all Site G track-makers appear to have been moving together: the G1 and G3 hominins walked over the Laetoli ashes together in parallel, following behind the G2 hominin.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"50 1","pages":"205 - 217"},"PeriodicalIF":0.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87128674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182299
Mostafa Oukassou, Omar Zafaty, G. Gierliński, H. Klein, H. Saber, Mustapha Amzil, A. Charrière
Abstract We describe an isolated small stegosaur pes track from the ?Upper Jurassic-?Lower Cretaceous red beds of the folded Middle Atlas, Morocco. It comes from the base of the Oued El Atchane Formation which unconformably overlies the Middle Jurassic (Upper Bathonian-? Callovian) El Mers III Formation. The footprint is preserved as concave epirelief together with a natural cast on a fluvial sandstone slab and is assigned here tentatively to cf. Stegopodus isp. The new discovery confirms the presence of this ichnogenus on the African continent and highlights similarities between the Jurassic-Cretaceous dinosaur faunas of North Africa and those of Asia, North America and Western Europe.
摘要:我们描述了上侏罗统-?摩洛哥中阿特拉斯褶皱的下白垩世红层。它来自Oued El Atchane组的底部，该组不整合地覆盖在中侏罗统(上Bathonian-?Callovian) El - Mers III组。该脚印与河流砂岩板上的自然铸型一起被保存为凹面浮雕，在这里暂定为cf. Stegopodus isp。这一新发现证实了这种鱼属在非洲大陆的存在，并强调了北非侏罗纪-白垩纪恐龙群与亚洲、北美和西欧恐龙群之间的相似性。
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Pub Date : 2022-10-02DOI: 10.1080/10420940.2023.2182295
G. Mustoe
Abstract Fluvial strata in the Paleogene Chuckanut Formation contain a wealth of trace fossils that include both vertebrate and invertebrate ichnofossils. Vertebrate traces have received careful scrutiny, but invertebrate traces have not previously been described. Trace fossils occur in two sediment types. Mudstones deposited in subaqueous environments include highly bioturbated layers that are dominated by horizontal meniscate burrows. Siltstone and fine-grained sandstone beds primarily contain vermiform trails on bedding surfaces, with sparse vertical traces. Some of these sandy beds also contain vertebrate tracks. Chuckanut Formation beds commonly show rapid facies changes in sediments that were deposited along a meandering river during a time of semitropical climate. Transitions from subaqueous to subaerial conditions may have been related to changing water levels caused by variations in seasonal precipitation or episodic flood events. Other possible factors include ponds created by abandonment of channels, overbank sediment s deposited by floods, and breaching of levees to form crevasse splay deposits. Trace fossil assemblages show local variations in the diverse depositional environments of the Chuckanut Formation. Many of the ichnofossil suites clearly represent Scoyenia Ichnofacies, but some occurrences may involve overprinting of Scoyenia and Mermia ichnofacies.
{"title":"Invertebrate trace fossils from Paleogene fluvial strata in Western Washington, USA","authors":"G. Mustoe","doi":"10.1080/10420940.2023.2182295","DOIUrl":"https://doi.org/10.1080/10420940.2023.2182295","url":null,"abstract":"Abstract Fluvial strata in the Paleogene Chuckanut Formation contain a wealth of trace fossils that include both vertebrate and invertebrate ichnofossils. Vertebrate traces have received careful scrutiny, but invertebrate traces have not previously been described. Trace fossils occur in two sediment types. Mudstones deposited in subaqueous environments include highly bioturbated layers that are dominated by horizontal meniscate burrows. Siltstone and fine-grained sandstone beds primarily contain vermiform trails on bedding surfaces, with sparse vertical traces. Some of these sandy beds also contain vertebrate tracks. Chuckanut Formation beds commonly show rapid facies changes in sediments that were deposited along a meandering river during a time of semitropical climate. Transitions from subaqueous to subaerial conditions may have been related to changing water levels caused by variations in seasonal precipitation or episodic flood events. Other possible factors include ponds created by abandonment of channels, overbank sediment s deposited by floods, and breaching of levees to form crevasse splay deposits. Trace fossil assemblages show local variations in the diverse depositional environments of the Chuckanut Formation. Many of the ichnofossil suites clearly represent Scoyenia Ichnofacies, but some occurrences may involve overprinting of Scoyenia and Mermia ichnofacies.","PeriodicalId":51057,"journal":{"name":"Ichnos-An International Journal for Plant and Animal Traces","volume":"43 1","pages":"148 - 165"},"PeriodicalIF":0.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81627188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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