Alexander K. Hastings, B. Schubert, Jason R. Bourque, R. Hulbert
{"title":"北美洲东南部最古老的短吻鳄记录","authors":"Alexander K. Hastings, B. Schubert, Jason R. Bourque, R. Hulbert","doi":"10.26879/1223","DOIUrl":null,"url":null,"abstract":"The genus Alligator has been represented by large-bodied, predatory species in southeastern North America for at least 18 million years (early Miocene), in what is now the southeastern United States. However, the first occurrences of the genus were from a smaller-bodied species, A. prenasalis , known from South Dakota and Nebraska that are about 34 million years old (latest Eocene to earliest Oligocene). Ancestors of A. prenasalis were likewise small-bodied and are from the Great Plains. This 16 mil-lion-year-gap has left open questions regarding the arrival and body size shift of Alligator from what is now the Great Plains to southeastern North America. Recently studied fossil material from Florida exhibits the oldest occurrence of Alligator in the region (about 28–26 million years ago). A well-preserved premaxilla (UF 422816) bears the diagnostic premaxillary 'notch' of Alligator . Additional material from this and two other Oligocene sites in Florida are indicative of Alligator as well. These include well-devel-oped osteoderms, which suggest possible maturity at small body size. As of now, no records of larger Alligator from this time (or older) have been recovered from the region, possibly indicating body size may not have increased in Alligator until the Miocene","PeriodicalId":56100,"journal":{"name":"Palaeontologia Electronica","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Oldest record of Alligator in southeastern North America\",\"authors\":\"Alexander K. Hastings, B. Schubert, Jason R. Bourque, R. Hulbert\",\"doi\":\"10.26879/1223\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The genus Alligator has been represented by large-bodied, predatory species in southeastern North America for at least 18 million years (early Miocene), in what is now the southeastern United States. However, the first occurrences of the genus were from a smaller-bodied species, A. prenasalis , known from South Dakota and Nebraska that are about 34 million years old (latest Eocene to earliest Oligocene). Ancestors of A. prenasalis were likewise small-bodied and are from the Great Plains. This 16 mil-lion-year-gap has left open questions regarding the arrival and body size shift of Alligator from what is now the Great Plains to southeastern North America. Recently studied fossil material from Florida exhibits the oldest occurrence of Alligator in the region (about 28–26 million years ago). A well-preserved premaxilla (UF 422816) bears the diagnostic premaxillary 'notch' of Alligator . Additional material from this and two other Oligocene sites in Florida are indicative of Alligator as well. These include well-devel-oped osteoderms, which suggest possible maturity at small body size. As of now, no records of larger Alligator from this time (or older) have been recovered from the region, possibly indicating body size may not have increased in Alligator until the Miocene\",\"PeriodicalId\":56100,\"journal\":{\"name\":\"Palaeontologia Electronica\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.0000,\"publicationDate\":\"2023-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Palaeontologia Electronica\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.26879/1223\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"Earth and Planetary Sciences\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Palaeontologia Electronica","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.26879/1223","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
Oldest record of Alligator in southeastern North America
The genus Alligator has been represented by large-bodied, predatory species in southeastern North America for at least 18 million years (early Miocene), in what is now the southeastern United States. However, the first occurrences of the genus were from a smaller-bodied species, A. prenasalis , known from South Dakota and Nebraska that are about 34 million years old (latest Eocene to earliest Oligocene). Ancestors of A. prenasalis were likewise small-bodied and are from the Great Plains. This 16 mil-lion-year-gap has left open questions regarding the arrival and body size shift of Alligator from what is now the Great Plains to southeastern North America. Recently studied fossil material from Florida exhibits the oldest occurrence of Alligator in the region (about 28–26 million years ago). A well-preserved premaxilla (UF 422816) bears the diagnostic premaxillary 'notch' of Alligator . Additional material from this and two other Oligocene sites in Florida are indicative of Alligator as well. These include well-devel-oped osteoderms, which suggest possible maturity at small body size. As of now, no records of larger Alligator from this time (or older) have been recovered from the region, possibly indicating body size may not have increased in Alligator until the Miocene
期刊介绍:
Founded in 1997, Palaeontologia Electronica (PE) is the longest running open-access, peer-reviewed electronic journal and covers all aspects of palaeontology. PE uses an external double-blind peer review system for all manuscripts. Copyright of scientific papers is held by one of the three sponsoring professional societies at the author''s choice. Reviews, commentaries, and other material is placed in the public domain. PE papers comply with regulations for taxonomic nomenclature established in the International Code of Zoological Nomenclature and the International Code of Nomenclature for Algae, Fungi, and Plants.