Mancallinae is an extinct subfamily of prehistoric flightless alcids that lived on the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

coast of today's

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

and

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

from the late

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

epoch to the early

Pleistocene The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed ...

(ranging from at least 7.4 million to 470,000 years ago). They are sometimes collectively referred to as Lucas auks after the scientist who described the first

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

, Frederic Augustus Lucas.

Description

They had

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation te ...

along somewhat similar lines as the

great auk The great auk (''Pinguinus impennis'') is a species of flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus ''Pinguinus''. It is not closely related to the birds now known as penguins, w ...

, their

North Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe and ...

ecological Ecology () is the study of the relationships between living organisms, including humans, and their biophysical environment, physical environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosy ...

counterpart, but their decidedly stubbier wings were in some aspects more convergent with

penguin Penguins ( order Sphenisciformes , family Spheniscidae ) are a group of aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapt ...

s. Compared with the subarctic great auk, they were also smaller (''see also:''

Bergmann's Rule Bergmann's rule is an ecogeographical rule that states that within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, while populations and species of smaller size are found in warmer ...

): ''Praemancalla'' species have been estimated to have weighed about 3 kg. Most ''Mancalla'' forms weighed somewhat less (about 2.4 kg), with ''M. milleri'' being a smaller (1.65 kg) and ''M. emlongi'' a much larger bird (3.8 kg) than the rest. The last species thus stood around 55–60 cm high in life. The largest species, ''Miomancalla howardi'', was the largest charadriiforme of all time.Smith, N. 2015. Evolution of body mass in the Pan-Alcidae (Aves, Charadriiformes): the effects of combining neontological and paleontological data. Paleobiology. doi: 10.1017/pab.2015.24

Evolution and classification

In a 2011 paper, N. Adam Smith published a review and revision of the Mancallinae. Smith defined Mancallinae as the clade containing ''Mancalla'', ''Miomancalla'', their common ancestor and all its descendants. A summary of his results follows. *Pan-

Alcidae An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...

Smith, 2011 **Mancallinae L.Miller, 1946 ***'' Mancalla'' Lucas, 1901 ****''Mancalla californiensis'' Lucas, 1901 ****''Mancalla cedrosensis'' Howard, 1971 ****''Mancalla lucasi'' Smith, 2011 ****''Mancalla vegrandis'' Smith, 2011 ***'' Miomancalla'' Smith, 2011 ****''Miomancalla howardi'' (Smith, 2011) ****''Miomancalla wetmorei'' (Howard, 1976) The following species could not be identified as unquestionable mancallines, and have been assigned to Pan-Alcidae ''incertae sedis''. They may be mancallines, or more closely related to true

auk An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (au ...

s. *''Alcodes ulnulus'' Howard, 1968 *''Mancalla diegensis'' Miller, 1937 *''Mancalla milleri'' Howard, 1970 The following species could not be differentiated from other recognized species of mancallines (see above), and have been assigned to Mancallinae ''incertae sedis''. *''Mancalla emlongi'' Olson, 1981 *''Praemancalla lagunensis'' Howard, 1966 The mancallines probably evolved from proto-

puffin Puffins are any of three species of small alcids ( auks) in the bird genus ''Fratercula''. These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in c ...

s, which must have been birds not dissimilar to the

rhinoceros auklet The rhinoceros auklet (''Cerorhinca monocerata'') is a seabird and a close relative of the puffins. It is the only extant species of the genus ''Cerorhinca''. Given its close relationship with the puffins, the common name rhinoceros puffin has b ...

. Accordingly, their status as a subfamily has been questioned as this would make the Alcinae (true auks)

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

. However, the mancallines were a very distinct and unique evolutionary lineage and are thus usually retained as a subfamily. They must have diverged from flying ancestors during the mid-Miocene, roughly 15 mya. ''Alcodes'' is known from a single

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

found in Late Miocene (

Clarendonian The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 13,600,000 to 10,300,000 years BP, a period of . It is ...

, 9–12 mya) deposits at

Laguna Hills Laguna Hills (; ''Laguna'', Spanish for "Lagoon") is a city in south Orange County, California, United States. Its name refers to its proximity to Laguna Canyon and the much older Laguna Beach. Other newer cities nearby— Laguna Niguel and L ...

. While assignment of such a fragmentary fossil is always problematical, the ulna is a fairly distinctive bone and that of ''Alcodes'' is quite peculiar. However, it is more allied with the Mancallines as a matter of convenience; additional material would be needed to confirm this relationship. From the bone's measurements, it seems probable that this species was flightless and judging from its age, it either represents an earlier development parallelling ''Mancalla'', or a third lineage of flightless auks. ''Praemancalla'' is known from Clarendonian to Early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

evolved from one of the two known species. ''Mancalla'' was a common species throughout the Pliocene, appearing in the

Hemphillian The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered ...

stage of the Late Miocene (5–9 mya), and spreading in the Pliocene, with 4 species apparently coexisting at one time on the coast of southern California. As with many marine birds, the mancalline auks were much affected by the extinction crisis in the late Pliocene oceans. This coincided with the diversification of

marine mammals Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their r ...

, but may ultimately have been caused by increased supernova activity in the vicinity of the solar system. Despite their apparent awkwardness, they seem to have been quite well adapted for flightless birds, with the fossil record suggesting that the last remnants did not disappear until the Early Pleistocene (c. 7 mya), some time after the ecological changes had passed their peak.

References

{{Taxonbar, from=Q3285302 Auks Extinct flightless birds Neogene birds Bird subfamilies