''Yongdongaspis'', colloquially known as the Binhai Yongdong, is an extinct genus of

galeaspid Galeaspida (from Latin, 'Helmet shields') is an extinct taxon of jawless marine and freshwater fish. The name is derived from ''galea'', the Latin word for ''helmet'', and refers to their massive bone shield on the head. Galeaspida lived in shallo ...

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

s within the monotypic family Yongdongaspididae. The type species is ''Y. littoralis'' and it was found in the

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

-aged Huixingshao Formation of

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. This makes it the oldest known

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

fossil discovered in

Chongqing ChongqingPostal Romanization, Previously romanized as Chungking ();. is a direct-administered municipality in Southwestern China. Chongqing is one of the four direct-administered municipalities under the State Council of the People's Republi ...

to date.

Discovery and naming

The holotype was excavated in July 2020 and was prepared in 2021, before being named as the new species ''Yongdongaspis littoralis'' in July 2022.

Description

Based on the holotype, ''Yongdongaspis'' only grew to around long.

References

Galeaspida Prehistoric jawless fish genera Fossil taxa described in 2022 Prehistoric animals of China Silurian jawless fish Chongqing {{paleo-jawless-fish-stub