Pholidota

The folidotos (Pholidota, "covered with scales" in ancient Greek) form an order of placental mammals, popularly known as pangolins. The order contains eight living species, all belonging to the genus Manis, one of four that make up the family Manids.

In the past, there was a greater diversity of pangolins, up to six different families. Pangolins have large scales on their skin - they are the only mammals to have them - and they live in the tropical regions of Africa and Asia. They have no teeth, and catch ants and termites with their long, narrow, sticky tongue. They are generally nocturnal, using their well-developed sense of smell to find the insects they feed on, but the long-tailed pangolin is also active. during the day. Pangolins spend most of the day sleeping curled up in a ball. The name pangolin comes from the Malay peng-guling ("the one that rolls up").

Description

Arboreal Pangolín hanging from the tail.

Dimensions of pangolins vary between the smallest species, the long-tailed pangolin (which measures 30-40 cm, but has a 60-70 cm tail) and the largest, the giant pangolin (75- 85 cm and a tail of 65-80 cm). A giant pangolin specimen reached a weight of 33 kg. In general, females are smaller than males.

Pangolins have a small, conical, elongated skull, one of the simplest of all mammals. Although their ears are very small or absent, pangolins have well-developed hearing. Their sense of smell is also well developed; instead, they have rather poor eyesight.

Pangolín rolled to protect himself.

Pangolins are characterized by having large hardened scales in the form of plates that cover the entire body except the snout, face, belly, and inner part of the limbs. These plates are soft in newborn pangolins, but harden as the animal grows. The plates are made of keratin, the same material that human fingernails, animal claws, or rhino horns are made of.. For this reason, pangolins look like a walking pineapple or artichoke. When threatened, pangolins roll up into a ball, using the plates as a form of armor and hiding their faces under their tails. The defensive function of these scales is enhanced by the fact that they are very sharp and can be controlled by the animal through special muscles, and can be used to injure any animal that tries to stick its snout or paw inside the shell. Its tongue is extraordinarily long and muscular; arises from the thorax between the sternum and the trachea, on the animal's chest. As a result, the tongue and associated muscles are longer than the head and body, allowing the pangolin to stretch out its tongue in surprising ways. Pangolins lack teeth. In contrast, the pyloric area of its stomach is thick and muscular, with projections of keratinous spines inward. It usually contains pebbles, which it uses to crush food.

They have short legs, with sharp claws that they use both for digging into termite and ant nests and for climbing trees. These are robust legs, and the hind legs are longer than the front ones. The claws on the front feet are so long that they are not well adapted for walking, so pangolins walk with their front feet tucked in to protect them. For this reason, pangolins move quite slowly, although in some cases they can run on their hind legs alone, balancing on their tails and reaching speeds of 5 km/h. They can also release foul-smelling acid from some glands near the anus, in a manner similar to skunks.

Behavior

Pangolins are shy and solitary animals, usually nocturnal, that spend the day inside their burrow. When they are inside the burrow, they cover it with earth and do not open it until they have to come out again. Unlike other animals that always remain in the same area, pangolins tend to roam more over wide regions, marking territory. Most commonly, females live alone with their young, if they have any, but on some occasions they share a den with a male.

For reasons explained above, pangolins are primarily bipedal animals. They are also good swimmers, who can move with some ease in the water, and thanks to their prehensile tail, they are good climbers. At the same time, they are not capable of moving quickly in any of these environments, so their defense The main thing is to roll up on itself to protect the soft parts of its body with the scales. This armor can resist the attack of hyenas and most cats.

Food

A pangolin from El Cabo digs into a nest of termites to feed.

Pangolins are myrmecophagous; they have a well-developed sense of smell, which they use to find termite and ant nests. Once they have found the insect nests, they dig with their feet to get them outside, where they catch them with their long tongue (which in the largest pangolins can be as long as 40 centimeters, but with a diameter of only half a centimeter). The tongue is covered by a mucous secretion from the salivary glands that helps catch insects more easily. A pangolin can eat up to 200,000 ants a day. Unlike other mammals, and in common with the anteater or bat Anoura fistulata, pangolins do not have their tongue attached to the hyoid bone, so when they are not using it, the tongue rests in a cavity in the thorax between the sternum and the trachea.

Since they have no teeth, pangolins do not chew their prey before swallowing it. For this reason, they usually swallow small stones and grains of sand, which are used to grind the prey inside the stomach. The stomach is armored with a hard, spiky epithelium that protects pangolins from the bites and venom of ants and termites. In Asian species, the stomach outlet presents two small "pyloric tips" that are capable of breaking down even the toughest exoskeleton.

The tree pangolin doesn't just search for insect nests, but sometimes uses its tail to hang from a tree branch, tearing away the bark to find termites lurking beneath. Since in some cases the insects that pangolins feed on can offer aggressive resistance, these mammals have developed special protection. They are able to close their nostrils and ears, and their eyes are protected by armored eyelids.

Playback

A calf of pangolin.

Pangolins reach sexual maturity at the age of 2 years. While African species usually have one young per gestation, Asian species can have between one and three. Pangolins can breed at any time of the year, although births are most frequent between November and March. As they are usually solitary animals, males and females have to find each other by following the scent trail. Gestation lasts between 4 and 5 months, except in the case of the Philippine pangolin, which only lasts two. months.

Pangolin babies are born with a length of approximately 15 centimeters and a weight of approximately 330 grams, but these measurements differ between different species. At birth, the hatchlings already have their eyes open, but their scales are still soft. Also, the hardening process begins very early, usually within two days of hatching. The mothers protect their young by keeping them attached to their coiled bodies and, like all mammals, they are in charge of feeding them with milk that they produce in their only pair of breasts.

The young are dependent on the mother until they are three to four months old. One month after hatching, they emerge from the burrow for the first time and begin to feed on termites. During these outings, the cubs remain very close to the mother (in some cases, they are even perched on the base of the tail) so that if it detects any danger, the cub can quickly hide under the mother as she rolls up for protection. and thus at the same time be able to protect yourself.

Distribution and habitat

Distribution of current pangolines (gender) Manis)

African pangolins inhabit southern and central Africa, from Sudan and Senegal in the north to South Africa in the south. Asian pangolins range across the southwest of the continent, from Pakistan in the west to Borneo in the east. In all the regions where they live, pangolins are suffering from the constant loss of their habitat, due in large part to the expansion of agriculture and other human activities. Specimens of long-tailed pangolins and Malayan pangolins have been found in cultivated areas, indicating that pangolins are being forced to venture close to humans.

African species inhabit forests and scrubs, as well as savannahs. On the other hand, Asian species live in tropical forests, meadows, and plains. In some cases they have been observed in areas degraded by human activity. Most pangolins live on land, inside burrows dug by themselves or by other animals (such as the aardvark), while the long-tailed pangolin and Tree pangolins live in the canopy of forests, and rarely come ashore. The Indian pangolin is also capable of climbing trees, but it burrows underground, so it is considered terrestrial.

Taxonomy

Formerly, pangolins were classified within the edentate class, which also included xenarthros, such as the anteater, the sloth, or the armadillo, which have a certain resemblance to pangolins. But new genetic evidence indicates that they are in fact part of the superorder Laurasiatheria, and that their closest living relatives are the carnivores, together with which they form the clade Ferae. Thus, it is apparent that the physical resemblances to anteaters and other similar animals are just one example of convergent evolution. Some paleontologists classify pangolins within the order Cimolesta, along with some extinct groups.

Order Pholidota

The order includes 17 genera distributed in six families and three additional genera that have not been assigned to any family, according to the following list:

Carlos Linneo described the genre Maniswhich includes all living species of pangolin.

Necromanis franconica (literally, "pangolín de Francia") is an extinct species of pangolín of the Miocene de France.

• Not assigned to any family
  • Gender Articanodon † (Rose) et al.2004)
  • Gender Melaniella † (Fox, 1984)
  • Gender Tubulodon † (Jepsen, 1932)

• Eomanidae family † (Storch, 2003)
  • Gender Eomanis † (Storch, 1978)
• Epoicotheriidae † (Simpson, 1927)
  • Gender Amelotabes (Rose, 1978)
  • Gender Dipassalus (Rose) et al.1991)
  • Gender Epoicotherium (Simpson, 1927)
  • Gender Tetrapassalus (Simpson, 1959)
  • Gender Xenocranium (Colbert, 1942)
• Escavadodontidae † (Rose ' Lucas, 2000)
  • Gender Escavadodon (Rose ' Lucas, 2000)
• Family Manidae (Gray, 1821)
  • Gender Manis (Linneo, 1758)
  • Gender Necromanis † (Filhol, 1893)
  • Gender Teutomanis † (Ameghino, 1905)
• Metacheiromyidae † (Wortman, 1903)
  • Gender Brachianodon (Gunnell " Gingerich, 1993)
  • Gender Metacheiromys (Wortman, 1903)
  • Gender Mylanodon (Secord) et al.2002)
  • Gender Palaeanodon (Matthew, 1918)
  • Gender Propalaeanodon (Rose, 1979)
• Family Patriomanidae † (Szalay & Schrenk, 1998)
  • Gender Cryptomanis (Gaudin) et al.2006)
  • Gender Patriomanis (Emry, 1970)

Genus Manis

The 8 extant species of pangolin all belong to the genus Manis ("spectrum" in Latin, from the same etymological root as "Manes", due to their nocturnal life and their unusual appearance). There are 4 species that inhabit Asia and another 4 in Africa. This genus is divided into 5 subgenres.

Manis Subgenre

Indian Pangolín

Indian Pangolín in Sikkim.

The Indian pangolin (Manis crassicaudata, Latin for "fat-tailed spectrum") lives in Pakistan, Bangladesh, much of India, some places in Sri Lanka and Yunnan (China). It inhabits a wide variety of ecosystems, including jungles, forests, plains, or the slopes of mountains.

It measures between 45 and 75 centimeters, with a tail between 33 and 45 centimeters. As in the other species, the males are often larger than the females. The scales are yellow-brown or greyish in color, and represent between a quarter and a third of the animal's body mass. It has five claws on each foot, three of which are adapted for digging. CITES has banned export in an attempt to protect the species.

It lives mainly inside burrows, the depth of which varies between 2 and 6 meters, depending on the hardness of the soil, but it is also capable of climbing trees. It is considered a curious animal and its main predator is the tiger. It has been the victim of hunting for its supposed medicinal value. The International Union for Conservation of Nature (IUCN) lists this species as "near threatened".

Chinese Pangol

The Chinese pangolin (Manis pentadactyla, Latin for "5-fingered spectrum") lives in Nepal, Bhutan, possibly Bangladesh, northern India, Burma, northern Indochina, passing through southern China and Taiwan. Lives in subtropical and deciduous forests; in Nepal, these ecosystems include many termite nests. It is a shy animal, which does not show any aggressive behavior.

The length of its body is between 40 and 60 centimeters, while the tail measures between 27 and 38 centimeters. It has a small head with a pointed snout and is bronze in color. It has strong legs and claws, which allow it to dig a burrow two meters deep in less than 5 minutes. The IUCN lists this species as Near Threatened. Hong Kong law protects this species, and efforts are underway to conserve it, but the inability to patrol the reserves where they live makes it easy for poachers to hunt them down.

Following the outbreak of COVID-19 in January 2020, Chinese scientists concluded that this species may have acted as an intermediate host for the SARS-CoV-2 virus.

Subgenus Paramanis

Pangolín of the Philippines

The Philippine pangolin (Manis culionensis, "Culion's spectrum" in Latin) is only found on the island of Palawan in the Philippines. It inhabits primary and secondary forests in the lowlands. It is fairly common, but is threatened by intensive hunting. Philippine pangolins may have originally been a Malayan pangolin population, which arrived in Palawan from Borneo during the early Pleistocene, via land bridges left behind. discovered when the sea level dropped during the ice age. When the ice began to melt on Earth and the sea level rose again, the population of Palawan was isolated and began the specialization process that would lead to the appearance of M. culionensis.

Malaysian Pangolín

A Malaysian pangoon going up to a tree.

The Malayan pangolin (Manis javanica, Latin for "Java spectrum") lives in Southeast Asia, including Thailand, Indonesia, the Philippines, Vietnam, Laos, Cambodia, Malaysia and Singapore. It lives in tropical forests, savannahs, and areas with dense vegetation, but occasionally wanders into cultivated land such as plantations or orchards. The skin on its feet is granulated, and its front legs are endowed with a kind of pads. The skin on the rest of the body is a grayish or bluish hue, and the little hair that covers its face and belly ranges from white to light brown.

In this species, fighting between males to get a mate has been observed. This, together with marked sexual dimorphism, indicates that this pangolin is at least partially polygynous. On the other hand, the females are the only ones in charge of caring for the young, after a gestation that lasts about 130 days. The pups weigh between 100 and 500 grams at birth; their weight is likely to be related to that of their parents

It is a species very close to the Chinese pangolin and the Philippine pangolin, but it is larger than these, it is lighter in color, and the claws on its front feet are shorter. Its main predators are the tiger and the clouded leopard. The IUCN lists this species as Near Threatened.

Smutsia subgenus

Pangolín de El Cabo

Pangolín de El Cabo in South Africa.

The Cape pangolin (Manis temminckii, "Temminck's spectrum" in Latin) lives in virtually all countries in the southern half of Africa, from Sudan and Ethiopia in the north to South Africa, Namibia and Mozambique in the south. Although it is present in a very vast area, it is difficult to observe because it is a rare animal, victim of intensive hunting to make amulets with its scales and of fires that destroy its habitat. Although it is capable of digging its own burrow, it prefers to occupy burrows that other animals such as anteaters no longer use. They also tend to hide in places with dense vegetation. It can grow up to 1 meter in length, with a tail between 30 and 50 centimeters. It has a very small head in proportion to its body, very strong hind legs, and small front legs. The IUCN lists this species as Near Threatened, but the United States Fish and Wildlife Service considers it a threatened species.

Giant Pangoldin

The giant pangolin (Manis gigantea, Latin for "giant specter") lives in many countries in the southern half of Africa. The largest populations are concentrated in Uganda, Tanzania, and western Kenya. It lives in forests and savannahs in places where water is available. It is not found at high altitudes. They usually live alone, but cases of a couple living together with their young have been observed. When they are born, the young cannot yet move their legs, but they can move by crawling on their bellies.

It is the largest species of the genus, reaching up to 140 cm in length in the case of males and 120 cm in females. Although the average weight is not known, a heavy giant pangolin weighed 33 kg. The giant pangolin uses this weight as a weapon when attacking ant or termite nests; it drops its weight on the nest at the same time that it strikes with its claws, causing the nest to sink rapidly. Its scales are brown or reddish brown. The only hair on its entire body are its eyelashes.

Subgenus Phataginus

Aboriginal Pangolín

The tree pangolin (Manis tricuspis, Latin for "three-cusped spectrum") lives in central and western Africa, ranging from the Democratic Republic of the Congo in the east to the southern tip of Senegal in the west, including the Niger River and Congo River basins. Sleeps in the forks of tree branches or lying among plants. When coiled it is capable of extending its scales and making cutting movements, using muscles to move the scales back and forth. It makes aggressive sounds when it feels threatened.

Females have small territories, less than 40,000 m², that rarely overlap. Males have larger ones, up to 200,000 m² with many female territories, causing encounters between the male and the females. These encounters are brief unless the female is in the mating season. Gestation lasts about 150 days, after which a single calf is usually born. The pups usually weigh between 90 and 159 gr. at birth. In captivity, there are records of females having adopted another mother's calf.

Subgenus Uromanis

Long tail pangolin

The long-tailed pangolin (Manis tetradactyla, Latin for "4-fingered spectrum") lives in the forests of a vast area of Africa sub-saharan; from the Atlantic coast between Guinea and Angola, through the Central African Republic and the Democratic Republic of the Congo, to Sudan and Uganda. Despite its long tail, which gives it its name, and which averages about 60 centimeters in length, this is the smallest species of pangolin, at 30 to 40 centimeters in body length. Like other pangolins, it is a nocturnal insectivore. Its scales are dark brown. It has no scales on the tip of its tail, which allows it to be used to cling to branches. The bald part of the tail could also be a sensory zone. Thanks to its size and its prehensile tail, it has an almost entirely arboreal lifestyle. It lives in the treetops of the jungle. Its abdomen is not covered with scales, but with dark fur. It has 46-47 tail vertebrae, more than any other known mammal, surpassing the 42-43 caudal vertebrae of Leptictidium auderiense.

Regarding the way of reproducing, the specimens of this species wrap their tails around each other, so that they are face to face. The length of gestation is not known, but young do not reach sexual maturity until the age of 2 years.

Evolution

Recreation of Eurotamandua joresi, the most basal member of the pangolins who, unlike their descendants, had no armor.

Although the pangolin appeared about 60 million years ago, during the Paleocene, the earliest known pangolins date to about 50 million years ago. They are Eomanis and Eurotamandua, both known from fossils found at the Messel Fossil Site, from the Eocene. While the affiliation to the genus Eurotamandua is not yet entirely certain and may be a Xenarthra, it has been shown that Eomanis is definitely a pangolin. These animals differed from modern pangolins: Eurotamandua did not have the typical scales, while Eomanis had them on the body, but not on the tail or legs. Contents found within the excellently preserved stomach of Eomanis at Messel show that it contained insects and plants; Richter and Storch suggested the possibility that pangolins originally fed on plants and stole leaves from leafcutter ants, ingesting a few insects accidentally. According to Richter and Storch, this would be the process by which pangolins would have begun to become myrmecophages.

Metacheiromys is a prehistoric pangolin from the middle Eocene of Wyoming. As in the case of its European relative Eurotamandua, it had no protective scales, and its head was different from that of today's pangolins; in fact it was more similar to that of the Armadillos, which made me consider him a Xenarthra. Its body was long and short and measured approximately 45 cm in length.

Tubulodon is the most primitive member of the palaenodont family, a suborder that appeared in the Eocene and still had some teeth, but was beginning to display some adaptations that characterize modern pangolins., especially with regard to adaptations for burrowing. Another family of pangolins that appeared in the late Eocene was the Patriomanids. The two genera it contains, Cryptomanis and Patriomanis, had already developed typical features of modern pangolins, but still retained features of primitive mammals such as a convex talus head or a prominent third trochanter, which are no longer found in modern pangolins. According to some scientists, the discovery of Crytomanis is an indication of the origin of pangolins in Eurasia.

By the Miocene, some 30 million years later, pangolins had already evolved a lot. Necromanis, a genus of French pangolin described by Henri Filhol in 1893, descended from Eomanis and already had an anatomy, diet, and behavior very similar to modern pangolins. Fossils have been found in the Quercy region.

In captivity

A bowl of mesh made of scales of Indian Pangolín, unique of its kind and presented to Jorge III in 1820.

Various pangolin species are kept in zoos, although captive breeding and breeding of pangolins is rarely successful, possibly because of their particular dietary needs or the fact that most pangolins that come to zoos or conservation centers have been confiscated from traffickers who kept them in poor condition. 71% of pangolins in captivity die within a year and only 11.5% exceed two and a half years.

However, there have been cases where some specimens have thrived in zoos. A pangolin lived 13 years in captivity and a baby Indian pangolin was born on 7 November 2006 at the Orissa Zoo. The zoo implemented a pangolin conservation program that built specially designed pangolin breeding enclosures., to later release them into nature.

Threats

Four of the pangolin species (the Cape pangolin, the Indian pangolin, the Chinese pangolin, and the Malayan pangolin) are listed as Near Threatened by the IUCN, which has created a task force specifically dedicated to protecting pangolins. Populations of these species have declined in recent years.

There are several threats to pangolins. Some of their predators such as the python or felines such as tigers, lions, or leopards. On the other hand, they may fall victim to fires that devastate their habitats, especially in Africa, or lose their habitat due to intensive agriculture and the abuse of pesticides.

However, the main threat to pangolins is hunting by humans. Pangolins are hunted for food in many parts of Africa and are one of the most popular types of bushmeat. Pangolins are also in high demand in China because their meat is considered a delicacy, and some Chinese (as well as some Africans) believe that pangolin scales reduce inflammation, improve blood circulation, and help women in the bathroom. lactation period to produce milk. This, along with deforestation, has caused a large decline in the number of giant pangolins.

Although they are prohibited, there are Chinese restaurants that continue to serve pangolin meat, selling at a price of between 50 and 60 euros per kg. One cook described how a pangolin is cooked:

We keep them alive in cages until a customer takes one. Then we leave them unconscious at hammer strokes, cut their necks and bleed them. It's a slow death. Then we boiled them to get the scales out. We cut the meat into small pieces and use it for various dishes, such as grilled meat or soup. Sometimes customers take their blood home.

Pangolin populations have been victims of illegal trafficking. For example, in May 2007, The Guardian newspaper reported that 31 pangolins had been found aboard an abandoned ship off the Chinese coast. The vessel contained some 5,000 endangered animals.

In November 2007, Thai customs officials reported that they had rescued more than 100 pangolins that were being smuggled out of the country, headed for China, where they were to be sold for cooking. Chinese pangolins are protected by Hong Kong law.