Post by Infinity Blade on Jul 7, 2020 9:49:18 GMT 5
Caribbean Monk Seal: Neomonachus tropicalis
Life restoration of a Caribbean monk seal. © @ Peter Schouten.
Temporal range: Holocene (extinct c. 1952 CE)
Scientific classification:
Life
Domain: Eukaryota
(unranked): Unikonta
(unranked): Opisthokonta
(unranked): Holozoa
(unranked): Filozoa
Kingdom: Animalia
Subkingdom: Eumetazoa
(unranked): Bilateria
Clade: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Clade: Cephalochordata
Clade: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Clade: Eugnathostomata
Clade: Teleostomi
Clade: Tetrapoda
Clade: Reptiliomorpha
Clade: Amniota
Clade: Synapsida
Clade: Eupelycosauria
Clade: Sphenacodontia
Clade: Sphenacodontoidea
Order: Therapsida
Clade: Eutheriodonta
Clade: Cynodontia
Clade: Epicynodontia
Clade: Eucynodontia
Clade: Probainognathia
Clade: Chiniquodontoidea
Clade: Prozostrodontia
Clade: Mammaliaformes
Class: Mammalia
Clade: Holotheria
Superlegion: Trechnotheria
Legion: Cladotheria
Sublegion: Zatheria
Infralegion: Tribosphenida
Subclass: Theria
Clade: Eutheria
Infraclass: Placentalia
Subcohort: Exafroplacentalia
Magnorder: Boreoeutheria
Superorder: Laurasiatheria
(unranked): Ferae
(unranked): Carnivoramorpha
Order: Carnivora
Suborder: Caniformia
Infraorder: Arctoidea
Clade: Pinnipedimorpha
Clade: Pinnipedia
Superfamily: Phocoidea
Family: Phocidae
Subfamily: Monachinae
Tribe: Monachini
Genus: Neomonachus
Species: †N. tropicalis
The Caribbean monk seal is an extinct species of monk seal that lived in the Caribbean until the mid-20th century.
Description:
Adults reached at least 2.4 meters in total body length; some slight sexual dimorphism may have been present, with females being slightly larger. If Hawaiian monk seals of similar body length are any indication, the largest recorded Caribbean monk seals would have weighed in the vicinity of 170-270 kg. The pups were likely about a meter long and 16-18 kg at birth.[1]
Adults were brown with a grayish tinge on the dorsal surface. The sides were lighter, which transitioned to a yellowish-white color on the ventral surface. Young individuals were more yellowish dorsally. These seals sometimes had green algae growing on their pelage like Hawaiian monk seals, which would have given them a greenish appearance.[1]
The dental formula was 2.1.5/2.1.5.[1]
The claws on the front flippers were well developed, but the claws on the hind flippers were merely simple points.[2]
Habitat:
Caribbean monk seals lived on isolated islands and atolls, typically in the middle of shallow water and reefs. They spent most of their time on sandy beaches exposed during times of high tide, but sometimes were found on near-shore rocks and rocky islets.[2]
Diet:
No one has ever scientifically studied the diet of Caribbean monk seals. Captive animals ate (and were presumably fed) fish and crabs.[2]
Ecology and behavior:
Only sharks and, of course, humans, are known to have preyed upon the Caribbean monk seal. Only one parasite has ever been identified from the Caribbean monk seal (the nasal mite Halarachne americana), although some unknown worms have been reported.[2]
These seals seemed to be rather unaggressive. They have been described as docile (making them vulnerable to hunters: see extinction section below)[2], and usually did not have many scars on their bodies (although one large male had substantial gashes and scars).[1]
Outside of the water, Caribbean monk seals had poor eyesight. When moving up onto land their groups numbered up to 500 individuals.[2] Interestingly, subadult seals would forage out in the night to avoid competition with adults, which foraged during the day time.[2]
Locomotion was typical of seals, hitching forward on land, and laterally undulating the spine while moving the hind flippers in the water.[2]
Extinction:
Christopher Columbus first discovered the Caribbean monk seal in 1494 during his second voyage to the Caribbean.[2][3] He referred to them as “sea wolves” and ordered his men to kill eight of them for food. This seems to have set the precedent for killing the monk seals.[3] Estimates on the Caribbean monk seal population pre-exploitation range from 338,000 to 680,000 individuals.[2] It would appear that the species evolved under environmental conditions with no large land predators, therefore never learning to flee or defend itself from predators[3] (although, the seals seem to have confined themselves to remote islands and atolls due to centuries of hunting by native peoples[2]), making themselves vulnerable to human hunters.[3]
After colonization, Caribbean monk seals were hunted extensively for a variety of purposes (skins, meat, and oil; the last was used for lubrication, cooking, and for lamps)[2] by fishermen, turtle hunters, buccaneers, and sealers (the last of whom organized themselves for the act).[3] Reportedly, up to 100 seals could be killed in one night in the Bahamas.[3] Caribbean monk seals still managed to be common into the 18th century[2], but by the late 19th century had been nearly driven to extinction.[2][3] In fact, it was thought by the mid-19th century that the seal was extinct, until a small group was found in the Yucatan Peninsula in 1886.[3] Once this population was found, killing once again continued, but this time for scientific study (the species was not well studied[3]), which must have exacerbated conditions.[2][3]
The last confirmed sighting of a Caribbean monk seal was in 1952 at Seranilla Bank (between Jamaica and Honduras)[2][3], where a small colony was reported to have lived in since then.[3] No subsequent sightings have been confirmed.[2][3] The species was definitively considered extinct by the IUCN since 1994.[4] After extensive surveys in the 1970s were conducted, one biologist, Karl Kenyon, stated that he believed the species to have been extinct since the early 1950s. Not only were no Caribbean monk seals spotted, but humans were everywhere. Kenyon remarked that even if some old individuals lived into the 1970s, the species would have had no chance of recovery given the overwhelming presence of humans.[3]
A captive Caribbean monk seal at the New York Aquarium c. 1910.
References:
[1] Jefferson, T. A., Webber, M. A., & Pitman, R. L. (2015). Marine mammals of the world: a comprehensive guide to their identification, 2nd edn San Diego.
[2] Best, T. L., & Hunt, J. L. (2020). Mammals of the Southeastern United States. University Alabama Press.
[3] Perrin, W. F., Würsig, B., & Thewissen, J. G. M. (Eds.). (2009). Encyclopedia of marine mammals. Academic Press.
[4] www.iucnredlist.org/species/13655/45228171
Life restoration of a Caribbean monk seal. © @ Peter Schouten.
Temporal range: Holocene (extinct c. 1952 CE)
Scientific classification:
Life
Domain: Eukaryota
(unranked): Unikonta
(unranked): Opisthokonta
(unranked): Holozoa
(unranked): Filozoa
Kingdom: Animalia
Subkingdom: Eumetazoa
(unranked): Bilateria
Clade: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Clade: Cephalochordata
Clade: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Clade: Eugnathostomata
Clade: Teleostomi
Clade: Tetrapoda
Clade: Reptiliomorpha
Clade: Amniota
Clade: Synapsida
Clade: Eupelycosauria
Clade: Sphenacodontia
Clade: Sphenacodontoidea
Order: Therapsida
Clade: Eutheriodonta
Clade: Cynodontia
Clade: Epicynodontia
Clade: Eucynodontia
Clade: Probainognathia
Clade: Chiniquodontoidea
Clade: Prozostrodontia
Clade: Mammaliaformes
Class: Mammalia
Clade: Holotheria
Superlegion: Trechnotheria
Legion: Cladotheria
Sublegion: Zatheria
Infralegion: Tribosphenida
Subclass: Theria
Clade: Eutheria
Infraclass: Placentalia
Subcohort: Exafroplacentalia
Magnorder: Boreoeutheria
Superorder: Laurasiatheria
(unranked): Ferae
(unranked): Carnivoramorpha
Order: Carnivora
Suborder: Caniformia
Infraorder: Arctoidea
Clade: Pinnipedimorpha
Clade: Pinnipedia
Superfamily: Phocoidea
Family: Phocidae
Subfamily: Monachinae
Tribe: Monachini
Genus: Neomonachus
Species: †N. tropicalis
The Caribbean monk seal is an extinct species of monk seal that lived in the Caribbean until the mid-20th century.
Description:
Adults reached at least 2.4 meters in total body length; some slight sexual dimorphism may have been present, with females being slightly larger. If Hawaiian monk seals of similar body length are any indication, the largest recorded Caribbean monk seals would have weighed in the vicinity of 170-270 kg. The pups were likely about a meter long and 16-18 kg at birth.[1]
Adults were brown with a grayish tinge on the dorsal surface. The sides were lighter, which transitioned to a yellowish-white color on the ventral surface. Young individuals were more yellowish dorsally. These seals sometimes had green algae growing on their pelage like Hawaiian monk seals, which would have given them a greenish appearance.[1]
The dental formula was 2.1.5/2.1.5.[1]
The claws on the front flippers were well developed, but the claws on the hind flippers were merely simple points.[2]
Habitat:
Caribbean monk seals lived on isolated islands and atolls, typically in the middle of shallow water and reefs. They spent most of their time on sandy beaches exposed during times of high tide, but sometimes were found on near-shore rocks and rocky islets.[2]
Diet:
No one has ever scientifically studied the diet of Caribbean monk seals. Captive animals ate (and were presumably fed) fish and crabs.[2]
Ecology and behavior:
Only sharks and, of course, humans, are known to have preyed upon the Caribbean monk seal. Only one parasite has ever been identified from the Caribbean monk seal (the nasal mite Halarachne americana), although some unknown worms have been reported.[2]
These seals seemed to be rather unaggressive. They have been described as docile (making them vulnerable to hunters: see extinction section below)[2], and usually did not have many scars on their bodies (although one large male had substantial gashes and scars).[1]
Outside of the water, Caribbean monk seals had poor eyesight. When moving up onto land their groups numbered up to 500 individuals.[2] Interestingly, subadult seals would forage out in the night to avoid competition with adults, which foraged during the day time.[2]
Locomotion was typical of seals, hitching forward on land, and laterally undulating the spine while moving the hind flippers in the water.[2]
Extinction:
Christopher Columbus first discovered the Caribbean monk seal in 1494 during his second voyage to the Caribbean.[2][3] He referred to them as “sea wolves” and ordered his men to kill eight of them for food. This seems to have set the precedent for killing the monk seals.[3] Estimates on the Caribbean monk seal population pre-exploitation range from 338,000 to 680,000 individuals.[2] It would appear that the species evolved under environmental conditions with no large land predators, therefore never learning to flee or defend itself from predators[3] (although, the seals seem to have confined themselves to remote islands and atolls due to centuries of hunting by native peoples[2]), making themselves vulnerable to human hunters.[3]
After colonization, Caribbean monk seals were hunted extensively for a variety of purposes (skins, meat, and oil; the last was used for lubrication, cooking, and for lamps)[2] by fishermen, turtle hunters, buccaneers, and sealers (the last of whom organized themselves for the act).[3] Reportedly, up to 100 seals could be killed in one night in the Bahamas.[3] Caribbean monk seals still managed to be common into the 18th century[2], but by the late 19th century had been nearly driven to extinction.[2][3] In fact, it was thought by the mid-19th century that the seal was extinct, until a small group was found in the Yucatan Peninsula in 1886.[3] Once this population was found, killing once again continued, but this time for scientific study (the species was not well studied[3]), which must have exacerbated conditions.[2][3]
The last confirmed sighting of a Caribbean monk seal was in 1952 at Seranilla Bank (between Jamaica and Honduras)[2][3], where a small colony was reported to have lived in since then.[3] No subsequent sightings have been confirmed.[2][3] The species was definitively considered extinct by the IUCN since 1994.[4] After extensive surveys in the 1970s were conducted, one biologist, Karl Kenyon, stated that he believed the species to have been extinct since the early 1950s. Not only were no Caribbean monk seals spotted, but humans were everywhere. Kenyon remarked that even if some old individuals lived into the 1970s, the species would have had no chance of recovery given the overwhelming presence of humans.[3]
A captive Caribbean monk seal at the New York Aquarium c. 1910.
References:
[1] Jefferson, T. A., Webber, M. A., & Pitman, R. L. (2015). Marine mammals of the world: a comprehensive guide to their identification, 2nd edn San Diego.
[2] Best, T. L., & Hunt, J. L. (2020). Mammals of the Southeastern United States. University Alabama Press.
[3] Perrin, W. F., Würsig, B., & Thewissen, J. G. M. (Eds.). (2009). Encyclopedia of marine mammals. Academic Press.
[4] www.iucnredlist.org/species/13655/45228171
