Cerdocyonina
Canidae·Carnivora
Cerdocyonina is an extant subtribe of canids native to the Americas, distinguished as a sister lineage to the subtribe Canina. This group, colloquially known as the South American canids, comprises 10 species that represent the most diverse array of canids found on any single continent. Their evolutionary history suggests origins in North America before migrating south.
Key Facts
- ›Cerdocyonina is an extant subtribe of canids endemic to the Americas.
- ›It is a sister lineage to the subtribe Canina.
- ›There are 10 extant species within this subtribe.
- ›Members are colloquially known as the South American canids.
- ›The group started diversifying between 3.9 and 3.5 million years ago from a common ancestor.
- ›Fossil evidence suggests an origin in North America before migration to South America.
South American Canids
North America, South America
About Cerdocyonina
The subtribe Cerdocyonina encompasses a diverse group of canids found exclusively in the Americas. Known colloquially as the South American canids, this lineage is a sister group to the subtribe Canina and represents the most varied collection of canids on any continent, with 10 extant species.
Evolutionary History and Taxonomy
Cerdocyonina's evolutionary journey suggests an origin in North America. Fossil evidence, such as that of Cerdocyon dating back 6-5 million years ago and Theriodictis and Chrysocyon from 5-4 million years ago, has been found in North America. A notable fossil of a large extinct Theriodictis, dated to 2 million years ago, was discovered in Florida. The presence of species like the maned wolf and an extinct crab-eating zorro in North America prior to the formation of the Isthmus of Panama further supports this North American origin before their migration south. Historically, taxonomic classifications varied, with some hypotheses proposing up to three genera and subgenera for these South American canids. However, modern morphological and DNA evidence confirms that these diverse adaptations form a distinct natural group within the Canidae family.
Genetic Lineage and Diversification
Genetic studies have shed significant light on the origins and diversification of Cerdocyonina. A 2022 study sequencing the genomes of living members indicated that the subtribe began to diversify from a common ancestor between 3.9 and 3.5 million years ago. This timeframe aligns with the ancestral arrival in South America from Central America via the Isthmus of Panama, after which the subtribe expanded to inhabit the entire continent.
Distinctive Characteristics
The Cerdocyonina can be identified by specific synapomorphies, or shared derived traits. These include a wide angular process of the mandible, which may lack a hook-like termination and features widened insertions for pterygoid muscle segments. They also possess a weak or absent posterior cusp on the p3 tooth and cristids joining the hypoconid and entoconid on the m1 tooth. Compared to the subtribe Canina, Cerdocyonina lacks a strongly arched zygoma and often the second posterior cusp on the p4, marking them as a more primitive lineage.
Source: Wikipedia ↗
Frequently Asked Questions
What are Cerdocyonina?
Cerdocyonina are an extant subtribe of canids found in the Americas. They are often referred to as the South American canids and represent a diverse group within the Canidae family.
Where do Cerdocyonina originate from?
Fossil records suggest that the common ancestor of Cerdocyonina originated in North America. This lineage later migrated to South America, likely through the Isthmus of Panama, and then expanded across the continent.
How many species are in Cerdocyonina?
There are 10 extant species that belong to the Cerdocyonina subtribe. This makes them the most diverse group of canids found on any single continent.
What is the evolutionary relationship of Cerdocyonina?
Cerdocyonina is a sister lineage to the subtribe Canina. Their common ancestor is estimated to have begun diversifying between 3.9 and 3.5 million years ago.
Are there any extinct members of Cerdocyonina?
Yes, the fossil record includes extinct members such as Theriodictis, which dates back millions of years. A study in 2018 also proposed that the extinct South American Canis gezi should be classified under Cerdocyonina.