Jump to content

Sparassodonta: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
No edit summary
No edit summary
Line 38: Line 38:


The early history of the Sparassodonta is poorly known, as most [[Paleocene]] and [[Eocene]] members of this group are only known from isolated teeth and fragmentary jaws. However, one species, the middle [[Eocene]] ''Callistoe vincei'', is known from a nearly complete, articulated skeleton.<ref>{{cite journal| title=''Callistoe vincei'' a new Proborhyaenidae (Borhyaenoidea, Metatheria, Mammalia) from the Early Eocene of Argentina|first=María J.|last=Babot|coauthor=Jaime E. Powell, Christian de Muizon|journal=[[Geobios]]|year=2002|volume=35|pages=615–629| url= http://www.sciencedirect.com/science/article/pii/S0016699502000736}}</ref> As ''Callistoe'' belongs to one of the most specialized groups of sparassodonts, this indicates that the other major groups (e.g. borhyaenids, hathliacynids, etc.) must have also arisen by this time. Originally, the early [[Paleocene]] [[metatherian]] ''[[Mayulestes]]'' was considered to be the earliest known member of the Sparassodonta, but phylogenetic analyses suggest that this species represents an independent radiation of carnivorous [[metatheria]]ns more closely related to ''[[Pucadelphys]]''.<ref>{{cite journal| title=Osteology of ''Arctodictis sinclairi'' (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America|first=Analía M.|last=Forasiepi|journal=[[Monografías del Museo Argentino de Ciencias Naturales]]|year=2009|volume=6|pages=1–174| url= http://www.academia.edu/4908872/Osteology_of_Arctodictis_sinclairi_Mammalia_Metatheria_Sparassodonta_and_phylogeny_of_Cenozoic_metatherian_carnivores_from_South_America}}</ref> As of this writing{{specify|date=December 2013}}, the earliest known true sparassodonts are either ''Allqokirus australis'', a species from the same site as ''Mayulestes'' which may also turn out to not be a sparassodont, and an isolated astragalus from the earliest [[Paleocene]] site of Punta Peligro, Argentina. <ref>{{cite journal| title=Additional data on early Paleocene metatherians (Mammalia) from Punta Peligro (Salamanca Formation, Argentina): comments based on petrosal morphology|first=Analía M.|last=Forasiepi|coauthor=Guillermo. W. Rougier|journal=[[Journal of Zoological Systematics and Evolutionary Research]]|year=2009|volume=4|pages=391–398| url= http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0469.2008.00519.x/abstract;jsessionid=41F66BF7A6B9D50439166C0C1C5B8B43.f03t02?systemMessage=Wiley+Online+Library+will+be+disrupted+on+7+December+from+10%3A00-15%3A00+BST+%2805%3A00-10%3A00+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage}}</ref> Marshall (1990) considered the [[Cretaceous]] [[stagodontids]] to also be a member of the Sparassodonta, but this was criticized by later authors.<ref>{{cite journal| title=Phylogenetic Relationships of the Families of Marsupials|first=Larry G.|last=Marshall|coauthors=J.A. Case, M.O. Woodburne|journal=[[Current Mammalogy]]|year=1990|volume=2|pages=433–505}}</ref>
The early history of the Sparassodonta is poorly known, as most [[Paleocene]] and [[Eocene]] members of this group are only known from isolated teeth and fragmentary jaws. However, one species, the middle [[Eocene]] ''Callistoe vincei'', is known from a nearly complete, articulated skeleton.<ref>{{cite journal| title=''Callistoe vincei'' a new Proborhyaenidae (Borhyaenoidea, Metatheria, Mammalia) from the Early Eocene of Argentina|first=María J.|last=Babot|coauthor=Jaime E. Powell, Christian de Muizon|journal=[[Geobios]]|year=2002|volume=35|pages=615–629| url= http://www.sciencedirect.com/science/article/pii/S0016699502000736}}</ref> As ''Callistoe'' belongs to one of the most specialized groups of sparassodonts, this indicates that the other major groups (e.g. borhyaenids, hathliacynids, etc.) must have also arisen by this time. Originally, the early [[Paleocene]] [[metatherian]] ''[[Mayulestes]]'' was considered to be the earliest known member of the Sparassodonta, but phylogenetic analyses suggest that this species represents an independent radiation of carnivorous [[metatheria]]ns more closely related to ''[[Pucadelphys]]''.<ref>{{cite journal| title=Osteology of ''Arctodictis sinclairi'' (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America|first=Analía M.|last=Forasiepi|journal=[[Monografías del Museo Argentino de Ciencias Naturales]]|year=2009|volume=6|pages=1–174| url= http://www.academia.edu/4908872/Osteology_of_Arctodictis_sinclairi_Mammalia_Metatheria_Sparassodonta_and_phylogeny_of_Cenozoic_metatherian_carnivores_from_South_America}}</ref> As of this writing{{specify|date=December 2013}}, the earliest known true sparassodonts are either ''Allqokirus australis'', a species from the same site as ''Mayulestes'' which may also turn out to not be a sparassodont, and an isolated astragalus from the earliest [[Paleocene]] site of Punta Peligro, Argentina. <ref>{{cite journal| title=Additional data on early Paleocene metatherians (Mammalia) from Punta Peligro (Salamanca Formation, Argentina): comments based on petrosal morphology|first=Analía M.|last=Forasiepi|coauthor=Guillermo. W. Rougier|journal=[[Journal of Zoological Systematics and Evolutionary Research]]|year=2009|volume=4|pages=391–398| url= http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0469.2008.00519.x/abstract;jsessionid=41F66BF7A6B9D50439166C0C1C5B8B43.f03t02?systemMessage=Wiley+Online+Library+will+be+disrupted+on+7+December+from+10%3A00-15%3A00+BST+%2805%3A00-10%3A00+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage}}</ref> Marshall (1990) considered the [[Cretaceous]] [[stagodontids]] to also be a member of the Sparassodonta, but this was criticized by later authors.<ref>{{cite journal| title=Phylogenetic Relationships of the Families of Marsupials|first=Larry G.|last=Marshall|coauthors=J.A. Case, M.O. Woodburne|journal=[[Current Mammalogy]]|year=1990|volume=2|pages=433–505}}</ref>

Sparassodonts can be divided into six major groups; '''basal sparassodonts''' (?earliest [[Paleocene]]-late [[Miocene]]), species that cannot be easily assigned to any of the other sparassodont groups and whose teeth often exhibit adaptations for [[omnivore|omnivory]]; '''hathliacynids''' (late [[Oligocene]]-early [[Pliocene]]/late[[Pliocene]]), which range from a [[marten]] to a [[thylacine]] in size, and have long, [[fox]]-like snouts and teeth strongly adapted for [[carnivore|carnivory]]; '''basal borhyaenoids''' (middle [[Eocene]]-late [[Miocene]], borhyaenoids that cannot be easily classified into the families [[Borhyaenidae]], [[Thylacosmilidae]], or [[Proborhyaenidae]] and vary in size and shape; '''borhyaenids''' (early-late [[Miocene]]), the sparassodont group most specialized for running, but not as much as living [[carnivorans]] or even [[thylacines]]; '''proborhyaenids''' (middle [[Eocene]]-late [[Oligocene]]), robust, [[wolverine]]-like forms with ever-growing upper and lower [[canines]]; and '''thylacosmilids''', another terrestrially specialized group with ever-growing saber-like upper [[canines]].<ref>{{cite journal| title=Osteology of ''Arctodictis sinclairi'' (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America|first=Analía M.|last=Forasiepi|journal=[[Monografías del Museo Argentino de Ciencias Naturales]]|year=2009|volume=6|pages=1–174| url= http://www.academia.edu/4908872/Osteology_of_Arctodictis_sinclairi_Mammalia_Metatheria_Sparassodonta_and_phylogeny_of_Cenozoic_metatherian_carnivores_from_South_America}}</ref> With the exception of some basal sparassodonts, all members of this group were [[hypercarnivorous]].<ref>{{cite journal| url=http://link.springer.com/article/10.1007/s10914-011-9175-9| title=The Evolution of the Cenozoic Terrestrial Mammalian Predator Guild in South America: Competition or Replacement?|first=Francisco J.|last=Prevosti|coauthor=Analia Forasiepi, Natalia Zimicz|journal=[[Journal of Mammalian Evolution]]|year=2013|volume=20|pages=3-21}}</ref> Based on studies of the postcranium, it appears as though most sparassodonts were [[scansorial]], but terrestrial adaptations evolved in ''"Lycopsis" longirostrus'', borhyaenids, proborhyaenids, and thylacosmilids.<ref>{{cite journal|url=http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.2011.00793.x/abstract?| title=Form and function within a phylogenetic framework: locomotory habits of extant predators and some Miocene Sparassodonta|first=Marcos D.|last=Ercoli|coauthor=Francisco J. Prevosti, Alicia Alvarez|journal=[[Zoological Journal of the Linnean Society]]|year=2012|volume=165|pages=224-251}}</ref>


==Classification==
==Classification==
The taxonomic classification below follows Forasiepi, 2009 (note the exclusion of ''[[Mayulestes]]'' and that the family Prothylacynidae is considered here as a [[paraphyletic]] assemblage of basal borhyaenoids)<ref>{{cite journal| title=Osteology of ''Arctodictis sinclairi'' (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America|first=Analía M.|last=Forasiepi|journal=[[Monografías del Museo Argentino de Ciencias Naturales]]|year=2009|volume=6|pages=1–174| url= http://www.academia.edu/4908872/Osteology_of_Arctodictis_sinclairi_Mammalia_Metatheria_Sparassodonta_and_phylogeny_of_Cenozoic_metatherian_carnivores_from_South_America}}</ref>
The taxonomic classification below follows the latest review of the group, that of Forasiepi, 2009 (note the exclusion of ''[[Mayulestes]]'' and that the family Prothylacynidae is considered here as a [[paraphyletic]] assemblage of basal borhyaenoids)<ref>{{cite journal| title=Osteology of ''Arctodictis sinclairi'' (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America|first=Analía M.|last=Forasiepi|journal=[[Monografías del Museo Argentino de Ciencias Naturales]]|year=2009|volume=6|pages=1–174| url= http://www.academia.edu/4908872/Osteology_of_Arctodictis_sinclairi_Mammalia_Metatheria_Sparassodonta_and_phylogeny_of_Cenozoic_metatherian_carnivores_from_South_America}}</ref>


* '''Order Sparassodonta'''
* '''Order Sparassodonta'''

Revision as of 20:32, 3 December 2013

Sparassodonta
Temporal range: Paleocene-Pliocene
Thylacosmilus
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Infraclass:
Metatheria
Order:
†Sparassodonta

Ameghino, 1894
Families

†Hathliacynidae
†Borhyaenidae
†Proborhyaenidae
†Prothylacinidae
†Thylacosmilidae

Sparassodonta is an extinct order of carnivorous metatherian mammals native to South America. They were once considered to be true marsupials, but are now thought to be a sister taxon to them.[1][unreliable source?] A number of these mammalian predators closely resemble placental predators that evolved separately on other continents, and are cited frequently as examples of convergent evolution. They were first described by Florentino Ameghino, from fossils found in the Santa Cruz beds of Patagonia. Sparassodonts were present throughout South America's long period of "splendid isolation" during the Cenozoic; during this time they shared the niches for large warm-blooded predators with the flightless terror birds. Previously, it was thought that these mammals died out in the face of competition from "more competitive" placental carnivorans during the Pliocene Great American Interchange, but more recent research has showed that sparassodonts died out long before eutherian carnivores arrived in South America (aside from procyonids).[2]

Features

Although members of the order Sparassodonta showed many similarities with placental carnivores, they were not closely related and are a very good example of convergent evolution. For example, sparassodonts' molars were very similar to the sharp teeth of placental carnivores. The canines were also lengthened, and in some cases resemble those of saber-toothed cats. Sparassodonts spanned a wide range of body sizes, from 2.2 pound (1 kg) weasel or civet-like forms to Thylacosmilus, which was the size of a leopard.[3][4]

The early history of the Sparassodonta is poorly known, as most Paleocene and Eocene members of this group are only known from isolated teeth and fragmentary jaws. However, one species, the middle Eocene Callistoe vincei, is known from a nearly complete, articulated skeleton.[5] As Callistoe belongs to one of the most specialized groups of sparassodonts, this indicates that the other major groups (e.g. borhyaenids, hathliacynids, etc.) must have also arisen by this time. Originally, the early Paleocene metatherian Mayulestes was considered to be the earliest known member of the Sparassodonta, but phylogenetic analyses suggest that this species represents an independent radiation of carnivorous metatherians more closely related to Pucadelphys.[6] As of this writing[specify], the earliest known true sparassodonts are either Allqokirus australis, a species from the same site as Mayulestes which may also turn out to not be a sparassodont, and an isolated astragalus from the earliest Paleocene site of Punta Peligro, Argentina. [7] Marshall (1990) considered the Cretaceous stagodontids to also be a member of the Sparassodonta, but this was criticized by later authors.[8]

Sparassodonts can be divided into six major groups; basal sparassodonts (?earliest Paleocene-late Miocene), species that cannot be easily assigned to any of the other sparassodont groups and whose teeth often exhibit adaptations for omnivory; hathliacynids (late Oligocene-early Pliocene/latePliocene), which range from a marten to a thylacine in size, and have long, fox-like snouts and teeth strongly adapted for carnivory; basal borhyaenoids (middle Eocene-late Miocene, borhyaenoids that cannot be easily classified into the families Borhyaenidae, Thylacosmilidae, or Proborhyaenidae and vary in size and shape; borhyaenids (early-late Miocene), the sparassodont group most specialized for running, but not as much as living carnivorans or even thylacines; proborhyaenids (middle Eocene-late Oligocene), robust, wolverine-like forms with ever-growing upper and lower canines; and thylacosmilids, another terrestrially specialized group with ever-growing saber-like upper canines.[9] With the exception of some basal sparassodonts, all members of this group were hypercarnivorous.[10] Based on studies of the postcranium, it appears as though most sparassodonts were scansorial, but terrestrial adaptations evolved in "Lycopsis" longirostrus, borhyaenids, proborhyaenids, and thylacosmilids.[11]

Classification

The taxonomic classification below follows the latest review of the group, that of Forasiepi, 2009 (note the exclusion of Mayulestes and that the family Prothylacynidae is considered here as a paraphyletic assemblage of basal borhyaenoids)[12]

  • Order Sparassodonta

References

  1. ^ Naish, Darren (29 June 2008). "Invasion of the marsupial weasels, dogs, cats and bears... or is it?". Tetrapod Zoology. Retrieved 2008-12-07. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
  2. ^ Prevosti, Francisco J. (2013). "The Evolution of the Cenozoic Terrestrial Mammalian Predator Guild in South America: Competition or Replacement?". Journal of Mammalian Evolution. 20: 3–21. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  3. ^ Prevosti, Francisco J. (2013). "The Evolution of the Cenozoic Terrestrial Mammalian Predator Guild in South America: Competition or Replacement?". Journal of Mammalian Evolution. 20: 3–21. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  4. ^ Ercoli, Marcos D. (2011). "Estimacion de masa de las especies de Sparassodonta (Mammalia, Metatheria) de edad Santacrucense (Mioceno Temprano) a partir del tamano del centroide de los elementos apendiculares: inferencias paleoecologicas". Ameghiniana. 48: 462–479. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  5. ^ Babot, María J. (2002). "Callistoe vincei a new Proborhyaenidae (Borhyaenoidea, Metatheria, Mammalia) from the Early Eocene of Argentina". Geobios. 35: 615–629. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  6. ^ Forasiepi, Analía M. (2009). "Osteology of Arctodictis sinclairi (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America". Monografías del Museo Argentino de Ciencias Naturales. 6: 1–174.
  7. ^ Forasiepi, Analía M. (2009). "Additional data on early Paleocene metatherians (Mammalia) from Punta Peligro (Salamanca Formation, Argentina): comments based on petrosal morphology". Journal of Zoological Systematics and Evolutionary Research. 4: 391–398. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  8. ^ Marshall, Larry G. (1990). "Phylogenetic Relationships of the Families of Marsupials". Current Mammalogy. 2: 433–505. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  9. ^ Forasiepi, Analía M. (2009). "Osteology of Arctodictis sinclairi (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America". Monografías del Museo Argentino de Ciencias Naturales. 6: 1–174.
  10. ^ Prevosti, Francisco J. (2013). "The Evolution of the Cenozoic Terrestrial Mammalian Predator Guild in South America: Competition or Replacement?". Journal of Mammalian Evolution. 20: 3–21. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  11. ^ Ercoli, Marcos D. (2012). "Form and function within a phylogenetic framework: locomotory habits of extant predators and some Miocene Sparassodonta". Zoological Journal of the Linnean Society. 165: 224–251. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  12. ^ Forasiepi, Analía M. (2009). "Osteology of Arctodictis sinclairi (Mammalia, Metatheria, Sparassodonta) and phylogeny of Cenozoic metatherian carnivores from South America". Monografías del Museo Argentino de Ciencias Naturales. 6: 1–174.
  13. ^ Forasiepi, Analía M. (2010). "A new thylacosmilid (Mammalia, Metatheria, Sparassodonta) from the Miocene of Patagonia, Argentina" (PDF). Zootaxa. 2552: 55–68. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)

Further reading

  • Ercoli, Marcos Darío (2012). "Form and function within a phylogenetic framework: locomotory habits of extant predators and some Miocene Sparassodonta (Metatheria)". Zoological Journal of the Linnean Society. 165 (1): 224–251. doi:10.1111/j.1096-3642.2011.00793.x. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
Wikisource has the text of the 1911 Encyclopædia Britannica article "Sparassodonta".


Stub icon

This prehistoric mammal-related article is a stub. You can help Wikipedia by expanding it.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Sparassodonta&oldid=584418774"