The biostratigraphy of the Tonasa Formation in the Jeneponto Regency of South Sulawesi, Indonesia, is still poorly known, and there are barren ages, such as much of the Oligocene to Early Miocene. The Tonasa Formation is well exposed along the coast of the Jeneponto Regency, in which the Karama area consists of the most important outcrops of this formation which in this area consists of interbedded marl and limestone. Our study focuses on the biostratigraphy of the Karama area section A based on nannofossil. Samples were collected by measured stratigraphy methods and then subjected to investigation using smear slides. The assemblages of species were determined by semiquantitative analysis. Data analysis obtained three nannofossil datums (boundaries): The First Occurrence (FO) of Sphenolithus pseudoradians NP19/NP20), the First Occurrence of Sphenolithus distentus (CP.16/CP.17), and the Last Occurrence (LO) Sphenolithus predistentus (NP.23/NP.24. The zonal boundary was determined based on calcareous nannoplankton; the Late Eocene to Middle Oligocene boundary of the Tonasa Formation was found in this section. Interestingly, throughout this period, the marker species in this section is Sphenolithus. In addition, the presence of Sphenolithus, Discoaster, and Zygrhablithus bijugatus indicated that the basin was in warm water condition.
{"title":"The Eocene to Oligocene boundary and paleoclimatic indications based on calcareous nannofossils of Tonasa Formation, South Sulawesi, Indonesia","authors":"M. Farida, A. Jaya, Asmita Ahmad, J. Nugraha","doi":"10.3897/fr.27.e96985","DOIUrl":"https://doi.org/10.3897/fr.27.e96985","url":null,"abstract":"The biostratigraphy of the Tonasa Formation in the Jeneponto Regency of South Sulawesi, Indonesia, is still poorly known, and there are barren ages, such as much of the Oligocene to Early Miocene. The Tonasa Formation is well exposed along the coast of the Jeneponto Regency, in which the Karama area consists of the most important outcrops of this formation which in this area consists of interbedded marl and limestone. Our study focuses on the biostratigraphy of the Karama area section A based on nannofossil. Samples were collected by measured stratigraphy methods and then subjected to investigation using smear slides. The assemblages of species were determined by semiquantitative analysis. Data analysis obtained three nannofossil datums (boundaries): The First Occurrence (FO) of Sphenolithus pseudoradians NP19/NP20), the First Occurrence of Sphenolithus distentus (CP.16/CP.17), and the Last Occurrence (LO) Sphenolithus predistentus (NP.23/NP.24. The zonal boundary was determined based on calcareous nannoplankton; the Late Eocene to Middle Oligocene boundary of the Tonasa Formation was found in this section. Interestingly, throughout this period, the marker species in this section is Sphenolithus. In addition, the presence of Sphenolithus, Discoaster, and Zygrhablithus bijugatus indicated that the basin was in warm water condition.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141365323","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}
We studied at least part of Kuhnʼs original material of lizards from the Paleocene (~MP 5) of the Walbeck locality in Germany. The collection was considered to be lost but is consistently discussed in the literature due to its importance. We restudied the type material of aff. Parasauromalus paleocenicus and aff. Glyptosaurus walbeckensis described by Kuhn in 1940. The former was originally allocated to Iguania, the latter to Anguimorpha, though later on these identifications were questioned by several authors. We show such a classification of both cannot be upheld. P. paleocenicus resembles the morphology of lacertids showing their presence in Europe already around MP 5. We consider the name P. paleocenicus as a nomen dubium. The material of aff. G. walbeckensis was later suggested to belong to Lacertidae and also considered as a potential amphisbaenian. Although it differs from modern amphisbaenians, it shares features with one supposed polyodontobaenid – Camptognathosaurus parisiensis. The Walbeck form is identical to this species. Since the Walbeck taxon was described in 1940, the principle of priority makes Camptognathosaurus parisiensis a junior synonym of the species erected by Kuhn. We propose a new combined name for this form, Camptognathosaurus walbeckensis comb. nov. The specimen figured by Kuhn is currently lost, thus we designate a neotype from Walbeck. However, this taxon differs significantly from Polyodontobaena and new data doubt the attribution of Camptognathosaurus to Amphisbaenia. This taxon is tentatively assigned here to Lacertidae, as further confirmed by phylogenetic analyses. Material of Scincoidea is also described.
{"title":"Roots of the European Cenozoic ecosystems: lizards from the Paleocene (~MP 5) of Walbeck in Germany","authors":"A. Čerňanský, D. Vasilyan","doi":"10.3897/fr.27.e109123","DOIUrl":"https://doi.org/10.3897/fr.27.e109123","url":null,"abstract":"We studied at least part of Kuhnʼs original material of lizards from the Paleocene (~MP 5) of the Walbeck locality in Germany. The collection was considered to be lost but is consistently discussed in the literature due to its importance. We restudied the type material of aff. Parasauromalus paleocenicus and aff. Glyptosaurus walbeckensis described by Kuhn in 1940. The former was originally allocated to Iguania, the latter to Anguimorpha, though later on these identifications were questioned by several authors. We show such a classification of both cannot be upheld. P. paleocenicus resembles the morphology of lacertids showing their presence in Europe already around MP 5. We consider the name P. paleocenicus as a nomen dubium. The material of aff. G. walbeckensis was later suggested to belong to Lacertidae and also considered as a potential amphisbaenian. Although it differs from modern amphisbaenians, it shares features with one supposed polyodontobaenid – Camptognathosaurus parisiensis. The Walbeck form is identical to this species. Since the Walbeck taxon was described in 1940, the principle of priority makes Camptognathosaurus parisiensis a junior synonym of the species erected by Kuhn. We propose a new combined name for this form, Camptognathosaurus walbeckensis comb. nov. The specimen figured by Kuhn is currently lost, thus we designate a neotype from Walbeck. However, this taxon differs significantly from Polyodontobaena and new data doubt the attribution of Camptognathosaurus to Amphisbaenia. This taxon is tentatively assigned here to Lacertidae, as further confirmed by phylogenetic analyses. Material of Scincoidea is also described.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140223132","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}
Although there are problematic earliest Jurassic records, phytosaurs are thought to have become extinct during the Rhaetian. A newly-discovered left paramedian phytosaur osteoderm from a clay pit in Bonenburg, Kreis Höxter, North Rhine-Westphalia, Germany, is the youngest, well-dated phytosaur record. This osteoderm was found in a bone bed (Bone Bed 2) in the Contorta Beds of the Rhaetian Exter Formation. Palynology constrains the age of Bone Bed 2 to the late middle Rhaetian (ca. 203.5 million years ago). The Bonenburg osteoderm cannot be assigned to any named species. It most closely resembles some osteoderms from the Rhaetian of Halberstadt in Central Germany. Phytosaurs survived in Europe to at least the late middle Rhaetian, probably falling victim to the end-Triassic extinction event about two million years later.
{"title":"A phytosaur osteoderm from a late middle Rhaetian bone bed of Bonenburg (North Rhine-Westphalia, Germany): Implications for phytosaur extinction","authors":"P. M. Sander, Paul W. Wellnitz","doi":"10.3897/fr.27.e114601","DOIUrl":"https://doi.org/10.3897/fr.27.e114601","url":null,"abstract":"Although there are problematic earliest Jurassic records, phytosaurs are thought to have become extinct during the Rhaetian. A newly-discovered left paramedian phytosaur osteoderm from a clay pit in Bonenburg, Kreis Höxter, North Rhine-Westphalia, Germany, is the youngest, well-dated phytosaur record. This osteoderm was found in a bone bed (Bone Bed 2) in the Contorta Beds of the Rhaetian Exter Formation. Palynology constrains the age of Bone Bed 2 to the late middle Rhaetian (ca. 203.5 million years ago). The Bonenburg osteoderm cannot be assigned to any named species. It most closely resembles some osteoderms from the Rhaetian of Halberstadt in Central Germany. Phytosaurs survived in Europe to at least the late middle Rhaetian, probably falling victim to the end-Triassic extinction event about two million years later.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140246264","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}
A new Darwin wasp species, Lithoserix oublierisp. nov. is described and illustrated from the early Oligocene limestone formation Calcaires de Campagne-Calavon in the Luberon Region, France. It represents the third species of this extinct genus, which was first described from the late Eocene Florissant Formation in Colorado, US and later found in Aix-en-Provence, France, from the late Oligocene. The taxonomic placement of this genus in the context of tribal classification is analysed and discussed, based on geometric morphometrics of the fore and hind wing venation of fossil and extant Pimplinae species. The results suggest that Lithoserix does not belong to the same group as the extinct genus Crusopimpla, but rather represents a more basal genus within Pimplini or belongs to an extinct separate tribe, closely related to Pimplini.
{"title":"Another one bites the dust: A new Lithoserix species (Hymenoptera, Ichneumonidae, Pimplinae) from the early Oligocene in France, with an evaluation of wing morphometrics","authors":"Alexandra Viertler","doi":"10.3897/fr.27.116373","DOIUrl":"https://doi.org/10.3897/fr.27.116373","url":null,"abstract":"A new Darwin wasp species, Lithoserix oublierisp. nov. is described and illustrated from the early Oligocene limestone formation Calcaires de Campagne-Calavon in the Luberon Region, France. It represents the third species of this extinct genus, which was first described from the late Eocene Florissant Formation in Colorado, US and later found in Aix-en-Provence, France, from the late Oligocene. The taxonomic placement of this genus in the context of tribal classification is analysed and discussed, based on geometric morphometrics of the fore and hind wing venation of fossil and extant Pimplinae species. The results suggest that Lithoserix does not belong to the same group as the extinct genus Crusopimpla, but rather represents a more basal genus within Pimplini or belongs to an extinct separate tribe, closely related to Pimplini.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139794364","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}
A new Darwin wasp species, Lithoserix oublierisp. nov. is described and illustrated from the early Oligocene limestone formation Calcaires de Campagne-Calavon in the Luberon Region, France. It represents the third species of this extinct genus, which was first described from the late Eocene Florissant Formation in Colorado, US and later found in Aix-en-Provence, France, from the late Oligocene. The taxonomic placement of this genus in the context of tribal classification is analysed and discussed, based on geometric morphometrics of the fore and hind wing venation of fossil and extant Pimplinae species. The results suggest that Lithoserix does not belong to the same group as the extinct genus Crusopimpla, but rather represents a more basal genus within Pimplini or belongs to an extinct separate tribe, closely related to Pimplini.
{"title":"Another one bites the dust: A new Lithoserix species (Hymenoptera, Ichneumonidae, Pimplinae) from the early Oligocene in France, with an evaluation of wing morphometrics","authors":"Alexandra Viertler","doi":"10.3897/fr.27.116373","DOIUrl":"https://doi.org/10.3897/fr.27.116373","url":null,"abstract":"A new Darwin wasp species, Lithoserix oublierisp. nov. is described and illustrated from the early Oligocene limestone formation Calcaires de Campagne-Calavon in the Luberon Region, France. It represents the third species of this extinct genus, which was first described from the late Eocene Florissant Formation in Colorado, US and later found in Aix-en-Provence, France, from the late Oligocene. The taxonomic placement of this genus in the context of tribal classification is analysed and discussed, based on geometric morphometrics of the fore and hind wing venation of fossil and extant Pimplinae species. The results suggest that Lithoserix does not belong to the same group as the extinct genus Crusopimpla, but rather represents a more basal genus within Pimplini or belongs to an extinct separate tribe, closely related to Pimplini.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139853950","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}
The historic collection of the Geological Survey of Alabama includes several fossil shark specimens that were recovered from the lower Paleocene Porters Creek Formation in southwestern Alabama, USA. Among these specimens are 17 teeth that we herein recognize as a new species within the extinct Paleogene genus, Palaeohypotodus. Detailed examination of these individual teeth, coupled with analyses of the dentitions of various extant lamniform sharks, allowed us to confirm monognathic and dignathic heterodonty within Palaeohypotodus. We identified upper and lower anterior and lateral tooth files that can be differentiated from one another by minor variations in morphology. Additionally, numerous isolated teeth from other Danian exposures in Alabama and Arkansas, USA, enhance our understanding of the composition of the dentition and ontogenetic heterodonty of both the new species and the genus as a whole.
{"title":"A new species of Palaeohypotodus Glückman, 1964 (Chondrichthyes, Lamniformes) from the lower Paleocene (Danian) Porters Creek Formation, Wilcox County, Alabama, USA","authors":"Jun A. Ebersole, D. Cicimurri, T. L. Harrell Jr.","doi":"10.3897/fr.27.e112800","DOIUrl":"https://doi.org/10.3897/fr.27.e112800","url":null,"abstract":"The historic collection of the Geological Survey of Alabama includes several fossil shark specimens that were recovered from the lower Paleocene Porters Creek Formation in southwestern Alabama, USA. Among these specimens are 17 teeth that we herein recognize as a new species within the extinct Paleogene genus, Palaeohypotodus. Detailed examination of these individual teeth, coupled with analyses of the dentitions of various extant lamniform sharks, allowed us to confirm monognathic and dignathic heterodonty within Palaeohypotodus. We identified upper and lower anterior and lateral tooth files that can be differentiated from one another by minor variations in morphology. Additionally, numerous isolated teeth from other Danian exposures in Alabama and Arkansas, USA, enhance our understanding of the composition of the dentition and ontogenetic heterodonty of both the new species and the genus as a whole.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139795052","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}
The historic collection of the Geological Survey of Alabama includes several fossil shark specimens that were recovered from the lower Paleocene Porters Creek Formation in southwestern Alabama, USA. Among these specimens are 17 teeth that we herein recognize as a new species within the extinct Paleogene genus, Palaeohypotodus. Detailed examination of these individual teeth, coupled with analyses of the dentitions of various extant lamniform sharks, allowed us to confirm monognathic and dignathic heterodonty within Palaeohypotodus. We identified upper and lower anterior and lateral tooth files that can be differentiated from one another by minor variations in morphology. Additionally, numerous isolated teeth from other Danian exposures in Alabama and Arkansas, USA, enhance our understanding of the composition of the dentition and ontogenetic heterodonty of both the new species and the genus as a whole.
{"title":"A new species of Palaeohypotodus Glückman, 1964 (Chondrichthyes, Lamniformes) from the lower Paleocene (Danian) Porters Creek Formation, Wilcox County, Alabama, USA","authors":"Jun A. Ebersole, D. Cicimurri, T. L. Harrell Jr.","doi":"10.3897/fr.27.e112800","DOIUrl":"https://doi.org/10.3897/fr.27.e112800","url":null,"abstract":"The historic collection of the Geological Survey of Alabama includes several fossil shark specimens that were recovered from the lower Paleocene Porters Creek Formation in southwestern Alabama, USA. Among these specimens are 17 teeth that we herein recognize as a new species within the extinct Paleogene genus, Palaeohypotodus. Detailed examination of these individual teeth, coupled with analyses of the dentitions of various extant lamniform sharks, allowed us to confirm monognathic and dignathic heterodonty within Palaeohypotodus. We identified upper and lower anterior and lateral tooth files that can be differentiated from one another by minor variations in morphology. Additionally, numerous isolated teeth from other Danian exposures in Alabama and Arkansas, USA, enhance our understanding of the composition of the dentition and ontogenetic heterodonty of both the new species and the genus as a whole.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139854756","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}
Jules Ferreira, Hugo Josse, Lucas Denadai de Campos, André Nel, Laure Desutter-Grandcolas
Fossil insects are valuable indicators of the evolutionary history of the clades to which they belong. According to their state of preservation, fossil insects are often partially described for key morphological characters, such as forewing venation in crickets (Orthoptera, Grylloidea). In parallel, the use of 3D microtomography is increasingly becoming common for studying some fossils, which allowed here the precise reconstruction and interpretation of the venation pattern in the smallest known cricket with a stridulatory apparatus, †Picogryllus carentonensis, found in opaque amber. The 3D reconstructions have revealed the general structure of the venation of the forewing and have enabled the identification of all its veins and cells, validating its similarity with that of extant crickets. Putative homologies are established according to previous studies, and some particularities are observed, such as the presence of two crossveins in the mirror, a rare feature in extant crickets that is discussed in the frame of cricket venation evolution. These findings highlight the importance of 3D microtomography as a powerful tool for examining fossil insects and also provide crucial information for taxonomic identification and evolutionary studies, offering a validated morphological basis for future phylogenetic analyses incorporating fossils.
{"title":"First 3D reconstruction of a forewing of a fossil Orthoptera: Interpreting the venation pattern in the smallest known cricket with a stridulatory apparatus, †Picogryllus carentonensis (Orthoptera, Grylloidea, Oecanthidae)","authors":"Jules Ferreira, Hugo Josse, Lucas Denadai de Campos, André Nel, Laure Desutter-Grandcolas","doi":"10.3897/fr.27.e113100","DOIUrl":"https://doi.org/10.3897/fr.27.e113100","url":null,"abstract":"Fossil insects are valuable indicators of the evolutionary history of the clades to which they belong. According to their state of preservation, fossil insects are often partially described for key morphological characters, such as forewing venation in crickets (Orthoptera, Grylloidea). In parallel, the use of 3D microtomography is increasingly becoming common for studying some fossils, which allowed here the precise reconstruction and interpretation of the venation pattern in the smallest known cricket with a stridulatory apparatus, †Picogryllus carentonensis, found in opaque amber. The 3D reconstructions have revealed the general structure of the venation of the forewing and have enabled the identification of all its veins and cells, validating its similarity with that of extant crickets. Putative homologies are established according to previous studies, and some particularities are observed, such as the presence of two crossveins in the mirror, a rare feature in extant crickets that is discussed in the frame of cricket venation evolution. These findings highlight the importance of 3D microtomography as a powerful tool for examining fossil insects and also provide crucial information for taxonomic identification and evolutionary studies, offering a validated morphological basis for future phylogenetic analyses incorporating fossils.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140488925","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}
Oligocene mysticetes display an unparalleled diversity and morphological disparity in the evolutionary history of Mysticeti. However, their paleoecological aspects, such as the patterns of coexistence of different morphotypes, remain poorly explored. Here we describe an aetiocetid (toothed mysticete) from the Jinnobaru Formation (lower upper Oligocene, about 28 million years ago) of Umashima Island, Kitakyushu, Japan. Our description of a toothed mysticete from the Oligocene of Umashima exemplifies the coexistence of toothed and baleen-assisted mysticetes in the northwestern Pacific. Hopefully, new finds of Oligocene mysticetes will lead to a well-sampled dataset for analyzing this and other related paleoecological traits to understand the demise of “archaic” Oligocene mysticetes and the subsequent rise of the modern-looking baleen-bearing whales in Miocene times.
{"title":"Coexistence of Oligocene toothed and baleen-assisted mysticetes in the northwestern Pacific","authors":"Cheng‐Hsiu Tsai, T. Kimura, Yoshikazu Hasegawa","doi":"10.3897/fr.27.e111567","DOIUrl":"https://doi.org/10.3897/fr.27.e111567","url":null,"abstract":"Oligocene mysticetes display an unparalleled diversity and morphological disparity in the evolutionary history of Mysticeti. However, their paleoecological aspects, such as the patterns of coexistence of different morphotypes, remain poorly explored. Here we describe an aetiocetid (toothed mysticete) from the Jinnobaru Formation (lower upper Oligocene, about 28 million years ago) of Umashima Island, Kitakyushu, Japan. Our description of a toothed mysticete from the Oligocene of Umashima exemplifies the coexistence of toothed and baleen-assisted mysticetes in the northwestern Pacific. Hopefully, new finds of Oligocene mysticetes will lead to a well-sampled dataset for analyzing this and other related paleoecological traits to understand the demise of “archaic” Oligocene mysticetes and the subsequent rise of the modern-looking baleen-bearing whales in Miocene times.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139626365","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}
D. Marjanović, Hillary C. Maddin, Jennifer C. Olori, Michel Laurin
The description of the small Late Triassic temnospondyl Chinlestegophis ushered in a potentially radically new understanding of the origins of the extant amphibian clades. Together with the fragmentary Rileymillerus, Chinlestegophis was argued to link extant caecilians to Permo-Triassic stereospondyl temnospondyls rather than to frogs and salamanders (and through them to amphibamiform temnospondyls or to brachystelechid and lysorophian “lepospondyls”). We critically review the comparative description of Chinlestegophis and phylogenetic analyses of previous studies. Most of the features previously interpreted to be shared by caecilians, Chinlestegophis and/or other stereospondyls have different distributions than scored in the analysis. We also find no evidence for an incipient tentacular sulcus in Chinlestegophis, and note that its vertebrae, unreduced ribs and dermal shoulder girdle are unlike those of any extant amphibians (nor their likely sister group, Albanerpetidae). Furthermore, the original matrices contain misscores accreted over more than a decade that likewise influence the results. Some features are coded as multiple redundant characters: the double toothrow of Chinlestegophis, other stereospondyls, and caecilians is represented as seven characters. Analysis of the unmodified matrix yields much less resolution than originally reported, and tree topology is altered by a small change to the taxon sample (the addition of Albanerpetidae), limited revisions of irreproducible scores, and ordering the most obviously clinal characters; any one of these changes removes Chinlestegophis from Lissamphibia, and confirms it as a stereospondyl.
{"title":"The new problem of Chinlestegophis and the origin of caecilians (Amphibia, Gymnophionomorpha) is highly sensitive to old problems of sampling and character construction","authors":"D. Marjanović, Hillary C. Maddin, Jennifer C. Olori, Michel Laurin","doi":"10.3897/fr.27.e109555","DOIUrl":"https://doi.org/10.3897/fr.27.e109555","url":null,"abstract":"The description of the small Late Triassic temnospondyl Chinlestegophis ushered in a potentially radically new understanding of the origins of the extant amphibian clades. Together with the fragmentary Rileymillerus, Chinlestegophis was argued to link extant caecilians to Permo-Triassic stereospondyl temnospondyls rather than to frogs and salamanders (and through them to amphibamiform temnospondyls or to brachystelechid and lysorophian “lepospondyls”). We critically review the comparative description of Chinlestegophis and phylogenetic analyses of previous studies. Most of the features previously interpreted to be shared by caecilians, Chinlestegophis and/or other stereospondyls have different distributions than scored in the analysis. We also find no evidence for an incipient tentacular sulcus in Chinlestegophis, and note that its vertebrae, unreduced ribs and dermal shoulder girdle are unlike those of any extant amphibians (nor their likely sister group, Albanerpetidae). Furthermore, the original matrices contain misscores accreted over more than a decade that likewise influence the results. Some features are coded as multiple redundant characters: the double toothrow of Chinlestegophis, other stereospondyls, and caecilians is represented as seven characters. Analysis of the unmodified matrix yields much less resolution than originally reported, and tree topology is altered by a small change to the taxon sample (the addition of Albanerpetidae), limited revisions of irreproducible scores, and ordering the most obviously clinal characters; any one of these changes removes Chinlestegophis from Lissamphibia, and confirms it as a stereospondyl.","PeriodicalId":55147,"journal":{"name":"Fossil Record","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139439553","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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