Guadeloupe ameiva—isolation, colonization & the end of an island species

Islands under pressure

The West Indies—including the Lesser Antilles—are among the most species-rich regions in the world. Many lizard and snake species are found exclusively there. These endemic species have adapted over millennia to the conditions of individual islands. Yet this very specialization makes them particularly vulnerable: when habitats are reshaped or new predators appear, the finely balanced island ecosystems quickly fall out of equilibrium.

How severe this development is was demonstrated by the herpetologists Robert Powell and Robert W. Henderson in an analysis: They concluded in 2005 that at least 37 of 81 endemic reptile species of the Lesser Antilles had been significantly impacted by human intervention. These include not only species with greatly reduced ranges but also those that have already gone extinct since European colonization—such as the Martinique ameiva (Pholidoscelis major), which is related to the Guadeloupe ameiva, or the Antiguan curly-tailed lizard (Leiocephalus cuneus).

Particularly at risk are reptile species that are active on the ground during the day and remain dependent on more pristine, open habitats. Such species often live in dry, light-rich coastal landscapes — habitats that were among the first to be altered or destroyed on many islands. The Australian naturalist David Corke pointed out as early as 1992 that precisely these species are among the most threatened reptiles of the Lesser Antilles. The Guadeloupe ameiva also fits this risk profile.

In addition to long-term pressures, there is another factor that hits island species particularly hard: extreme natural events. While hurricanes are part of the natural cycle of the Caribbean, their consequences are often exacerbated by degraded landscapes and rising sea levels. For very small, isolated populations, a single storm can be enough to tip the fragile balance once and for all.

In the case of the Guadeloupe ameiva, such an extreme event probably led to the extinction of the species. The Okeechobee Hurricane struck Guadeloupe in September 1928 with extraordinary force and destroyed large parts of the archipelago. Contemporary reports describe massive devastation of vegetation, agriculture, and settlements. For an already severely diminished ameiva population restricted to a small refuge, this storm meant the definitive end. Yet the hurricane was not the beginning of the end, but rather the final blow. The decline of the Guadeloupe ameiva had begun decades earlier.

Guadeloupe ameiva – fact sheet

alternative names	Guadeloupean groundlizard, Grand Islet ameiva, Grand Islet Guadeloupe ameiva
scientific names	Pholidoscelis cineraceus, Ameiva cineracea
original range	Grand-Îlet (Guadeloupe, Lesser Antilles, Caribbean)
time of extinction	no later than 1928
causes of extinction	hurricane, human use, possibly introduced predators and habitat loss
IUCN status	extinct

Grand Îlet: Range or last refuge?

The example of the Guadeloupe ameiva shows how difficult it is to reconstruct the original range of extinct island species. The last confirmed occurrence is clearly documented—the question of the former distribution, however, remains disputed.

In more recent historical times, the Guadeloupe ameiva was documented only on Grand Îlet off the town of Petit-Bourg. This Grand Îlet lies a few hundred meters off the east coast of Basse-Terre, the western of the two main islands of the Guadeloupe archipelago, which in turn belongs to the Lesser Antilles within the West Indies.

Grand Îlet is a very small, uninhabited coral island, densely covered with low vegetation. It is only about 150 meters long and 50 meters wide and thus considerably smaller than a square kilometer. On this islet, the American herpetologists Thomas Barbour and Gladwyn Kingsley Noble collected the last known living specimens of the Guadeloupe ameiva in 1914. Already at that time, they assumed that it was the last refuge of the species—an assessment that was later shared by experts such as Powell & Henderson.

Historical clues from the 17th century

French chroniclers of the 17th century, particularly Jean-Baptiste Du Tertre, described large, ground-dwelling lizards that were widespread on Guadeloupe. Such reports were long interpreted as evidence that the Guadeloupe ameiva was once widely distributed across the archipelago, including the main islands Basse-Terre and Grande-Terre as well as surrounding islands.

However, the historical texts are not unambiguous enough to reliably distinguish between different ameiva species. Above all, they describe “large ground-dwelling lizards” in general—and such lizards could well have belonged to several, in some cases now extinct, lineages in the Guadeloupe archipelago. The historical sources are therefore an important indication of formerly common large ground lizards on Guadeloupe, but not conclusive proof that they were all Guadeloupe ameivas.

Subfossil finds: Pholidoscelis almost everywhere—but which species?

Many researchers (such as Powell & Henderson 2009 or Regalado 2015) assume, based on subfossil finds, that the Guadeloupe ameiva was formerly distributed on the main island of Guadeloupe as well as on surrounding islands and islets (La Désirade, Les Saintes, Petite Terre, Marie-Galante, among others) and that its range gradually shrank over time—until finally only Grand Îlet remained.

Indeed, subfossil bone remains of lizards of the genus Pholidoscelis were found on nearly all islands of the Guadeloupe archipelago, including Basse-Terre, Grande-Terre, La Désirade, Petite Terre, Les Saintes, and Marie-Galante. Most of these bones come from archaeological deposits (i.e., from periods of human settlement), a smaller portion from paleontological layers (i.e., from periods before human settlement). Many of these finds had long remained without detailed examination.

In a study published in 2016, Corentin Bochaton and his team systematically analyzed these subfossil remains for the first time. The researchers found that species-level identification based on bones is extremely difficult: within the genus Pholidoscelis, strong morphological similarities exist, so that even between known species, reliable distinguishing features are scarce. Consequently, they had to work with size differences and geographical arguments, among other methods, to provisionally assign finds.

In the course of this work, they even described a previously unknown species that went extinct in the Holocene and occurred exclusively on the island of Marie-Galante: Pholidoscelis turukaeraensis. This find indicates that the reptile fauna of Guadeloupe was formerly more species-rich than long assumed—and that behind many bone finds there may be not just a single species, but several (in some cases now vanished) Pholidoscelis species.

Crucial for the Guadeloupe ameiva is the central caveat of the study: Bochaton et al. found no fossil evidence that Pholidoscelis cineracea specifically occurred outside Grand Îlet, where living specimens were collected in 1914. This represents the first evaluation that does not confirm the traditional assumption of a formerly wide distribution, but rather puts it into perspective.

What is thus established: Pholidoscelis lizards were formerly widespread across the entire archipelago. Whether they were all Guadeloupe ameivas or several, in some cases now extinct, species remains unclear to this day. A definitive resolution would probably only be possible with paleogenetic methods—but suitable material is not yet available.

Against this backdrop, the Guadeloupe islands indeed hold a special position: today they are completely free of living Pholidoscelis species. Meanwhile, subfossil finds suggest that ameiva diversity in the archipelago was formerly greater than long assumed—three species have been described so far (Guadeloupe ameiva, Martinique ameiva, and P. turukaeraensis from Marie-Galante). None of these lineages has survived to the present day.

The disappearance of the Guadeloupe ameiva

It is largely considered plausible that the hurricane that swept across the Guadeloupe archipelago in 1928 dealt the Guadeloupe ameiva the final death blow. Which factors promoted the decline beforehand, however, cannot be clearly determined to this day. As with many extinct island species, the picture does not emerge from a single cause, but from the interaction of multiple stresses.

The Guadeloupe ameiva was listed early on in supraregional overviews as extinct. René E. Honegger listed it in 1981 in his fundamental compilation of amphibians and reptiles that have vanished since the year 1600 as a lost island species of the Caribbean. He emphasized that the extinction of West Indian reptiles is rarely monocausal to explain, but usually the result of overlapping influences: habitat changes, human use, and introduced predators such as dogs, cats, rats, and mongooses are frequently cited together in the specialist literature.

Habitat loss—only if the species was formerly more widespread

The often-cited factor of habitat loss is not unproblematic in the case of the Guadeloupe ameiva. It assumes that the species formerly had stable populations on larger islands of the archipelago—particularly on the main island—and was displaced there through deforestation, agriculture, settlement construction, and landscape change.

Yet this very assumption was critically questioned by Bochaton et al. (2016): if there is indeed no reliable evidence for populations of the Guadeloupe ameiva outside Grand Îlet, then large-scale land use changes on Basse-Terre or Grande-Terre would hardly have played a direct role in the disappearance of the last population. In this scenario, the extreme small-scale nature of the habitat, a small population size, and the associated vulnerability to random events would instead be decisive.

This does not, however, rule out that “habitat loss” on a very small scale could also have an effect on such a small island as Grand Îlet—for example through erosion, vegetation changes, storm damage, or the loss of suitable egg-laying sites. The key point is: habitat loss only explains the extinction as the main driver if the species truly once occurred more widely across the archipelago.

Use by humans: Lizard meat and eggs

Another possible influencing factor is use by humans. Bochaton and his team found in 2016, when examining fossil bones, that a very small proportion (0.5%) of the remains of ameivas of the genus Pholidoscelis showed burn marks. From this they concluded that at least some animals were intentionally heated and presumably consumed. However, due to the low frequency of these traces, this does not constitute evidence of regular or intensive use. Nevertheless, the size and anatomical distribution of the finds suggest that ameivas may have been occasionally used by pre-Columbian populations (from about 500 BC).

Powell and Henderson also pointed out in 2005 that the use of reptiles by indigenous populations could in principle have played a role in the decline of some island species. For the Guadeloupe ameiva, however, there are no indications of permanent settlement of its last known habitat, Grand Îlet. Nonetheless, it is possible that such islets were visited from time to time by canoe—for fishing, gathering, or hunting. Even minor but repeated hunting pressure could have had noticeable effects on an already very small and isolated population. However, direct archaeological evidence that clearly demonstrates targeted use of the Guadeloupe ameiva specifically has not been found to date.

That large lizards in island ecosystems were generally used by humans is well documented from other regions. For example, the Cape Verde giant skink was specifically hunted—both as a food source and for processing its skin. Historical sources from the Caribbean also point to the use of large lizards. The French missionary Raymond Breton reported in the 17th century of lizards on Guadeloupe “that one eats on the islands” and that were sufficient “to feed three persons at a single meal.” He also mentioned the use of their eggs for sauces.

Which species exactly Breton described cannot be said with certainty today. Nevertheless, use of the Guadeloupe ameiva as a food source appears plausible, since ameivas of the Lesser Antilles can reach considerable sizes: the Martinique ameiva grew to about 50 centimeters in length, and the Guadeloupe ameiva likely reached a total length of around 35 to 45 centimeters including its tail.

Mongooses and other introduced species—cause or amplifier?

Introduced animal species are among the most important causes of island species extinction worldwide. In the Caribbean, this process began early: as early as about 500 BC, pre-Columbian populations brought rodents and dogs to the islands, either unintentionally or deliberately. With European colonization from the late 15th century, this development intensified greatly. Rats, cats, pigs, goats, and dogs arrived in the region in large numbers and—in addition to agriculture, urbanization, and habitat fragmentation—permanently altered the sensitive island ecosystems. Ground-dwelling reptiles, birds, and small mammals that had evolved without comparable predators were barely able to cope with these new threats.

A particularly consequential role was played by the deliberate introduction of the small Javan mongoose (Herpestes javanicus) from the 1870s onwards. It was released on numerous Caribbean islands to combat rats in sugarcane plantations—an ecological experiment that failed. Mongooses are diurnal, while rats are predominantly nocturnal. Instead of rats, the mongooses primarily hunted diurnally active prey: ground-dwelling lizards, snakes, amphibians, and ground-nesting birds. On many islands, their introduction was followed by a rapid decline or complete disappearance of such species.

Starting from early introductions, for example in Jamaica, the mongoose was deliberately or indirectly spread to numerous islands of the Greater and Lesser Antilles in the following decades. This process continued into the early 20th century. Several islands of the Lesser Antilles—including Martinique, St. Lucia, and Guadeloupe—were also colonized by mongooses during this period.

Against this backdrop, Powell and Henderson concluded in 2005 that the introduction of the Javan mongoose was the single most important factor in the decline of many reptile species of the Lesser Antilles. Indeed, on numerous islands, a striking temporal correlation can be observed between the appearance of the mongoose and the disappearance of ground-dwelling lizards such as ameivas.

This pattern also fits a general observation that Bochaton and his team (2016) emphasize: large, ground-dwelling, and diurnally active lizards are particularly vulnerable to human influences due to their biology. They represent an easily accessible food source and are at the same time preferentially preyed upon by introduced mammals such as cats, dogs, or mongooses. This combination is considered a central cause of the extinction of many squamate reptiles on islands.

For the Guadeloupe ameiva, this pattern initially explains its fundamental vulnerability. Whether introduced predators actually caused the extinction of the last population on Grand Îlet, however, is a different question.

Does this also apply to the Guadeloupe ameiva?

In the case of the Guadeloupe ameiva, the situation is more complex. As early as 1966, Jonathan N. Baskin and Ernest E. Williams warned against explaining the decline of West Indian reptiles monocausally. They emphasized that there is no automatic connection between the introduction of the mongoose and the extinction of a species. Similar reservations were also expressed by David Corke (1992), who pointed out that reliable evidence for the widely assumed key role of the mongoose is often lacking in individual cases.

For the Guadeloupe ameiva, Baskin & Williams found that while mongooses were introduced to Guadeloupe, the species there either never occurred on the main island or had already been severely pushed back—possibly even gone before the mongoose became established across the area. Furthermore, they point to comparison islands such as St. Martin or Grenada, where mongooses and ameivas were able to coexist for an extended period. Conversely, ameiva populations also disappeared on islands where mongooses were never introduced. The mongoose is thus an important factor for the regional context but does not necessarily explain the fate of a last isolated remnant population.

The crucial question again concerns the last refuge. If the Guadeloupe ameiva was indeed restricted to the small, uninhabited Grand Îlet from an early stage, classical explanations such as deforestation, agriculture, or urbanization largely lose their relevance—as does a direct role for the mongoose, which was probably never permanently present there. In this scenario, introduced predators would more likely be thought of as a pressure on possible populations on larger islands, not as a necessary cause of the final disappearance on Grand Îlet.

Multiple factors instead of a single cause

The extinction of the Guadeloupe ameiva therefore most likely appears as the result of multiple overlapping factors: an extremely small and isolated population, a tiny habitat, low genetic diversity, and a high vulnerability to random events. Under such conditions, natural disasters—particularly strong hurricanes—can mean the definitive end. The devastating hurricane of 1928 likely did deliver the final blow in this scenario.

Introduced predators such as mongooses, cats, or rats may have accelerated or intensified the decline on larger islands. However, they do not necessarily explain the extinction of the last population on an uninhabited offshore island. René E. Honegger (1981) also regarded the mongoose more as an additional stress factor than as the sole cause.

The Javan mongoose was undoubtedly one of the most consequential invasive species of the Caribbean. For the Guadeloupe ameiva, however, its extinction cannot be clearly attributed to it—especially if the species last survived exclusively on Grand Îlet. More probable is an interplay of extreme isolation, small population size, human use in a broader sense, long-term environmental changes, and finally a natural disaster. The mongoose would in this process be more of an amplifier—primarily outside the presumed last refuge.

When did the Guadeloupe ameiva go extinct?

Archaeological, paleontological, and historical evidence suggests that large Pholidoscelis lizards on Guadeloupe did not disappear suddenly but became rarer over an extended period. Bochaton and his team (2016) place the decline of these ameivas in the Guadeloupe archipelago temporally in the phase after European colonization. Their bone finds show that formerly several large, ground-dwelling ameiva forms occurred and were apparently present in considerable numbers.

Historical reports from the 17th century still mention ground-dwelling lizards on Guadeloupe as common. At that time, large ground lizards appear to have been a normal component of the island ecosystems. Importantly, however, these sources primarily demonstrate that large Pholidoscelis lizards were once widespread—not necessarily that P. cineracea itself occurred everywhere.

When the Guadeloupe ameiva was first scientifically described at the beginning of the 20th century, the picture was completely different. Barbour and Noble reported in 1915 of an extremely small and isolated population:

“Apparently confined to a small low-lying island locally known as Grand Isle (…). There can hardly be more than a dozen or two dozen specimens of this Ameiva there. Observations of the second author [Noble] on Guadeloupe suggest that this is the last place where the Guadeloupe ameiva still exists.”

This discrepancy is striking: between the reports of “numerous” large ground lizards in the 17th century and the documentation of a tiny remnant population at the beginning of the 20th century, there are roughly 200 years. This suggests that the formerly widespread Pholidoscelis lizards of Guadeloupe nearly completely vanished within roughly two centuries after the beginning of European settlement—in a phase during which landscape, land use, and species composition underwent fundamental changes. Honegger (1981) also noted that the Guadeloupe ameiva had already been in severe decline long before 1900.

Regarding the exact timing of the definitive extinction, uncertainty remains. The last confirmed observation of living Guadeloupe ameivas dates from 1914. After the Okeechobee Hurricane, which swept across Guadeloupe in September 1928, no ameivas could be detected on Grand Îlet. Accordingly, in the specialist literature—such as Day (1981), Honegger (1981), Regalado (2015), and in the IUCN Red List—the year 1928 is frequently cited as the time of extinction.

At the same time, it cannot be ruled out that the species had already disappeared before this storm. The IUCN interprets the extinction within the framework of a classic island retreat model: according to this, the species would have first suffered population losses on larger islands after European settlement and ultimately held on in offshore islets such as Grand Îlet.

This interpretation, however, assumes that the Guadeloupe ameiva was originally more widespread. Bochaton et al. (2016) qualify precisely this assumption, since so far no conclusive evidence exists for stable populations of P. cineracea outside Grand Îlet. If the species truly lived in an extremely confined area from the outset, its disappearance would more likely be the result of long-term isolation and random events—and 1928 would then be a plausible but unprovable endpoint.

What remains certain above all is this: 1914 is the last record of living animals, and at the latest after 1928 there are no further indications of survival. The hurricane would in this context probably not have been the beginning, but the last, random trigger of an already long-lasting decline.

Early mentions—and what they reveal about the way of life

Our knowledge of the Guadeloupe ameiva is based almost exclusively on early reports from the colonial era and on the examination of a few museum specimens. The oldest clues date from the 17th century, when missionaries and nature observers began to describe the fauna of the Caribbean—long before modern zoology existed.

One of the earliest and most important sources is the French Dominican monk Raymond Breton, who lived on Guadeloupe for several years from 1635. In his Dictionnaire caraïbe-français (first versions around 1658, printed around 1665), he describes under the entry “ouayhaca” a large land-dwelling lizard that, in the estimation of today’s experts, fits very well with an ameiva:

“Ouayhaca, a large land-dwelling iguana or large lizard, also a marine iguana. The land-dwelling lizard that one eats on the islands is sufficient to feed three persons at a single meal;
it makes a good soup when boiled, and its eggs are used to prepare a sauce. The males are gray, the females green on the back and golden on the underside; they lay their eggs in the sand.”

Even though Breton does not classify the lizard scientifically and the exact species must remain open, several points are noteworthy: he describes a large, ground-dwelling animal that was used as food—and he expressly mentions egg-laying in the sand. This is exactly what is typical for ameivas: they are oviparous, meaning egg-laying, and use loose, warm soil as a breeding substrate. The eggs develop there without parental care, aided by the warmth and moisture of the soil.

Another central source is the Dominican Jean-Baptiste Du Tertre, who in his multi-volume work Histoire générale des Antilles habitées par les François (1667–1671) described numerous animal species of the French Antilles based on his own observations. He too devoted attention to the large ground-dwelling lizards of Guadeloupe and recorded detailed behavioral observations:

“They stay on the ground and only come out in the hot hours of the day; then they gnaw on bones and fish bones thrown out in front of doors. Sometimes they eat grass, especially vegetables. When some are killed, others come along, tear them apart and eat them.”

This passage fits remarkably well with a large, diurnally active, ground-dwelling lizard with opportunistic feeding habits. It also suggests that such animals occurred near human settlements and responded flexibly to food sources—this ecological adaptability is also observed in present-day ameiva species.

On the appearance and way of life of the Guadeloupe ameiva

The original scientific description was not published until 1915 by Thomas Barbour and Gladwyn Kingsley Noble. It was based on three adult specimens that Noble collected on Grand Îlet near Petit-Bourg in 1914: one male and two females. These three animals remain the only reliably documented museum specimens to this day.

From them it can be deduced that the Guadeloupe ameiva was a slender, very agile ground lizard. The snout-vent length was about 15 centimeters; the tail was—as is typical for ameivas—considerably longer than the body. This yields an estimated total length of about 35 to 40 centimeters. Historical reports occasionally cite lengths of up to about 45 centimeters; this is not impossible, since the closely related Martinique ameiva was said to be even larger at up to 50 centimeters.

Barbour & Noble also described a long tail with keeled scales. Striking was an exceptionally high number of femoral pores on the inner thigh surfaces—about 31 per body side. These gland openings serve scent communication (e.g., territory and trail marking) and are species-specific within the teiid lizards; the high number lies at the upper end of what is known in the family.

The coloration is reported differently in the sources. Barbour & Noble describe a predominantly ash-gray dorsal surface with faintly suggested darker longitudinal stripes, bluish flanks, and a slightly olive-colored head and tail. The ventral surface was pale, straw-colored to milky. The species name cineracea (“ash-gray”) refers to this base coloration.

The comparison with Breton, however, shows how cautiously color features must be interpreted: Breton describes markedly more variable colors. Barbour & Noble, by contrast, found no clear sexual dimorphism in their three preserved museum specimens. This is probably due to the extremely small sample size and to color changes caused by preservation, since many ameiva species do in fact show sex-specific differences in coloration and body structure.

Baskin & Williams (1966) emphasized the particular distinctiveness of the species based on anatomical features of the few known specimens. Particularly notable was the very high number of 20 longitudinal rows of ventral scales—an extreme value within the ameivas of the Lesser Antilles. The rather uniform appearance of the preserved animals also caught their attention. However, this feature must be interpreted with caution, since 17th-century reports describe considerably more variable colors and it is known that preservation can greatly alter the original coloration.

Regardless of color questions, the combination of distinctive scalation and other anatomical features clearly distinguishes the Guadeloupe ameiva from closely related species, such as the Dominican ground lizard (P. fuscata) or the Saint Lucia whiptail (Cnemidophorus vanzoi) found on St. Lucia. This distinctiveness is today interpreted as an indication of a long, isolated evolutionary history.

Museum specimens: Few records

Only three reliably documented museum specimens of the Guadeloupe ameiva are known. The holotype (MCZ 10577) is housed in the Museum of Comparative Zoology. The two additional specimens were originally also held there, but their current whereabouts are not clearly documented. According to modern databases, at least one was later transferred to the Muséum national d’Histoire naturelle. Whether one or both specimens are still located there or whether further transfers occurred cannot be conclusively determined based on publicly accessible information.

Taxonomy: The special position of the Guadeloupe ameiva

The Guadeloupe ameiva belongs to the ameivas—large, very agile ground lizards within the family Teiidae. These lizards are distributed mainly in Central and South America as well as on Caribbean islands. For a long time, zoologists placed the Guadeloupe ameiva in the genus Ameiva, because it outwardly fit well into the then broadly conceived concept of this group.

Only modern genetic studies led to a fundamental reassessment. In 2016, a study led by the herpetologist Noemí Goicoechea showed that the traditionally very broadly conceived genus Ameiva conflated several evolutionarily distinct lineages—species that appeared similar were genetically not as closely related as assumed.

It became particularly clear that the ameivas of the West Indies form their own lineage, which diverged early from the continental species of Central and South America. To accurately reflect this relationship, the West Indian ameivas were placed back into a separate genus: Pholidoscelis. Since then, the Guadeloupe ameiva also officially bears the name Pholidoscelis cineracea.

Another genetic study confirmed this classification in the same year. Derek B. Tucker and his team examined hundreds of genetic markers in numerous ameiva species and showed that Pholidoscelis is clearly separated from the continental Ameiva species. The Caribbean ameivas thus form a clearly delineated, independent evolutionary lineage.

Remarkably, this special position had already been recognized before the genetic clarification: Baskin & Williams described the Guadeloupe ameiva in 1966 as exceptionally distinctive. Together with the likewise extinct Martinique ameiva, they placed it in a separate group, the so-called cineracea group, and emphasized that this species differs in many features more distinctly from other ameivas of the Lesser Antilles than any other known species in the region.

Evolutionary history: An ameiva without neighbors

Among the ameivas of the Lesser Antilles, the Guadeloupe ameiva occupies an unusual position. Unlike many of its relatives, it cannot be simply placed in a series of neighboring island populations based on either body structure or geographical location. As early as 1966, Baskin & Williams pointed out that the species clearly differs from all other ameivas in the region.

For many Caribbean ameivas, dispersal appears to have occurred step by step from island to island: on neighboring islands, closely related species or subspecies are therefore often found. This pattern is described as stepping-stone colonization. This pattern, however, is absent in the Guadeloupe ameiva.

Instead, Baskin & Williams discussed a “leap-frog” scenario: a lineage skips one or more islands and reaches its destination directly—for example through rare long-distance drift events on floating vegetation, triggered by storms or hurricanes. According to this idea, the ancestors of the Guadeloupe ameiva could have reached Guadeloupe directly without establishing permanent populations on intervening islands.

This model explains why the species was so isolated and why no clear sister species can be found on surrounding islands. It also fits the possibility that its range was small from the outset—perhaps limited to Guadeloupe or even to individual offshore islets. The fossil findings of Bochaton (2016) at least indirectly support the idea that the Guadeloupe ameiva was not simply part of a closely connected “island-to-island” network.

Physical characteristics as well—such as the distinctive ventral scalation and other anatomical features—also point to a long phase of isolation. Baskin & Williams interpreted these peculiarities as the result of a long, independent evolutionary history. With the extinction of the Guadeloupe ameiva, not only an island species was lost, but also an independent evolutionary lineage that could have provided insights into the early biogeographic history of the Caribbean.

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Sources

• Barbour, T. and Noble, G. K. (1915). A revision of the lizards of the genus Ameiva. Bulletin of the Museum of Comparative Zoology at Harvard College, 59. 417–479.
• Baskin, J. N., & Williams, E. E. (1966). The Lesser Antillean Ameiva (Sauria, Teiidae). Studies on the Fauna of Curaçao and other Caribbean Islands, 89. 144–176.
• Breton, R. (1665/1999). Dictionnaire caraïbe-français (M. Besada Paisa, J. Bernabé, S. de Pury, O. Renault-Lescure, M. Thouvenot & D. Troiani, Hrsg.). Paris, France: Karthala & IRD.
• Bochaton, C., Boistel, R., Grouard, S., et al. (2017). Evolution, diversity and interactions with past human populations of recently extinct Pholidoscelis lizards (Squamata: Teiidae) from the Guadeloupe Islands (FrenchWest-Indies). Historical Biology, 31(2). 1–17. https://doi.org/10.1080/08912963.2017.1343824
• Corke, D. (1992). The status and conservation needs of the terrestrial herpetofauna of the Windward Islands (West Indies). Biological Conservation, 62. 47–58. https://doi.org/10.1016/0006-3207(92)91151-H
• Day, D. (1981). The Doomsday Book of Animals: A Natural History of Vanished Species. London: Ebury Press.
• Dewynter, M. (2017). Pholidoscelis cineraceus. In The IUCN Red List of Threatened Species 2017: e.T1119A121639617. IUCN. https://doi.org/10.2305/IUCN.UK.2017-3.RLTS.T1119A121639617.en
• Du Tertre, J.-B. (1667). Histoire generale des isles de S. Christophe, de la Guadeloupe de la Martinique et autres dans l’Amerique. Langlois, Paris.
• Goicoechea, N., Frost, D. R., De la Riva, I., et al. (2016). Molecular systematics of teioid lizards (Teioidea/Gymnophthalmoidea: Squamata) based on the analysis of 48 loci under tree-alignment and similarity-alignment. Cladistics. https://doi.org/10.1111/cla.12150
• Honegger, R. E. (1981). List of amphibians and reptiles either known or thought to have become extinct since 1600. Biological Conservation. 141–158.
• Powell, R., & Henderson, R. W. (2005). Conservation status of Lesser Antillean reptiles. Iguana, 12(2), 62–77.
• Powell, R., & Henderson, R. W. (2012). Island lists of West Indian amphibians and reptiles. Bulletin of the Florida Museum of Natural History, 51(2). 148–159.
• Regalado, P. G. (2015). Los Anfibios y Reptiles Extinguidos: Herpetofauna Desaparecida Desde el Año 1500. Monografías de la Universidade da Coruña.
• Tucker, D. B., Colli, G. R., Giugliano, L. G., et al. (2016). Methodological congruence in phylogenomic analyses with morphological support for teiid lizards (Sauria: Teiidae). Molecular Phylogenetics and Evolution, 103. 75–84. https://doi.org/10.1016/j.ympev.2016.07.002