The New Mysterious Highland Flap-Necked Chameleons from East Africa, with remarks on the status of Chamaeleo roperi BOULENGER, 1890 and Chamaeleo martensi MERTENS, 1964 (Sauria: Chamaeleonidae) 

Petr Nečas

Corresponding author: petr.necas@me.com

Abstract

A review of the status of Chamaeleo roperi Boulenger, 1890 and Chamaeleo martensi Mertens, 1964, in the context of "Chamaeleo dilepis (Leach, 1819) complex" is provided, a new species, Chamaeleo incognitus, sp.n. is described from Kenyan Highlands.

Key words: Chamaeleonidae, new species, Chamaeleo roperi, Chamaeleo martensi, Chamaeleo incognitus sp.n., Kenya, Tanzania

Introduction

The aim of this study is to bring new information and previously unpublished evidence and possible interpretations into the area of systematics and taxonomy of the members of "Chamaeleo dilepis - complex" based on classical methods, and interdisciplinary use of data, not to do genetic studies. For the purpose of this study, only existing preserved specimens were used, no animals were killed. As evidence, the following approaches were used: observations in the wild, study of literature and museum voucher specimens and photographic evidence (partly Nečas 2025a-d). 

Brief history of the taxonomy of the "Chamaeleo dilepis - complex"

In 1819, Chamaeleon dilepis was described by Leach: in Bodwich, Mission from Cape Coast Castle to Ashantee, App. IV: 493. – Type locality: French Congo (= Republic of Congo). – Holotype (by monotypy): BMNH 1946.8.13.75. 


Chamaeleo dilepis is a species with probably the largest range within the family Chamaeleonidae. Forms, referred traditionally to this species, reach in sub-Saharan Africa from the Atlantic to Indian Ocean and south to South Africa. (Klaver & Böhme 1997; Necas 1999; Tilbury 2018). Its distribution covers various biomes, vegetation types, and climates. Although some generalist species (like Bitis arietans) can be distributed across a wide range of environments without corresponding strong genetic divergence at the species level (Barlow & al. 2013), such diverse environmental features, are typically implicated in promoting speciation by phylogenetic niche conservatism (Wiens, 2004).

The taxonomy of the forms belonging to the "Chamaeleo dilepis - complex" is still largely unresolved (see Tilbury 2010, 2018; Glaw 2015). Based on genetic analysis, it seems to consist of several cryptic lineages (Main & al. 2018, Main 2019) but there is a lot of confusion, as the data often miss precise location, some forms have not been sampled or included in the analysis (Chamaeleo ruspolii and Chamaeleo martensi) and some data are simply wrong (eg referring the highland records to lowland biomes and climatic zones). More detailed analyses need to be done to resolve all the open questions.

Currently, a list of synonyms is considered by Glaw (2015):

• Chamaeleo planiceps Merrem, 1820
• Chamaeleo bilobus Kuhl, 1820
• Chameleon dilepas Stutchbury, 1837 (ex errore)
• Chamaeleon dilepas Martin, 1838 (ex errore)
• Chamaeleon petersii var. kirkii Gray,1865
• Chamaeleo capellii Bocage,1866
• Chamaeleo angusticoronatus Barbour, 1903

The following forms represent separate subspecies or species (modified after Tilbury 2010; Glaw 2015; Nečas & al. 2025):

• Chamaeleo dilepis idjwiensis Loveridge, 1942 (Idjwi Island, Democratic Republic of Congo)
• Chamaeleo dilepis isabellinus Günther, 1893 (Shire Highlands, Malawi)
• Chamaeleo dilepis petersii Gray, 1865 (Mocambique, Malawi)
• Chamaeleo martensi Mertens, 1964 (Pemba Island, Tanzania)(see discussion)
• Chamaeleo quilensis Bocage, 1866 (Southern Africa)
• Chamaeleo roperi Boulenger, 1890 (Coastal Kenya, Tanzania)(see discussion)
• Chamaeleo ruspolii Boettger, 1893 (Haud, Somaliland and Ethiopia)

Ironically, the most widely distributed chameleon species (Chamaeleo dilepis - complex) has a scattered pattern of distribution due to habitat preference and suitable egg-laying / reproduction sites, and despite being vastly represented in the museum collections, the material is often mislabeled, wrongly identified, and often lacks precise coordinates. Many territories of its occurrence are hardly accessible due to security or logistic constraints, and obtaining material from such big area is quite challenging. This makes any analysis quite difficult and the current state of our understanding of its differentiation reflects this situation.

While morphological differences can be minimal between individual taxa, there is significant variation in the occipital lobe within "Chamaeleo dilepis - complex". This diversity has significantly contributed to the description of many forms, but the validity of these forms has been questioned and remains partly uncertain (Klaver & Böhme 1997; Largen & Spawls 2006; Spawls & al. 2018; Tilbury, 2018). Notably, the morphological variation among subspecies is not consistent, especially for traits like the presence or absence of tarsal spurs, squamation, the extent of dorsal and gular crest development, and occipital lobe development across their geographic ranges. Additionally, the appearance of distinct traits significantly overlap geographically (Tilbury 2018). Given that the taxonomy of chameleons of the genus Chamaeleo is quite old and is mainly based on morphological features (see Tilbury, 2018) and considering the minimal variation between some species but significant variation within a single species, it is possible that the genus Chamaeleo in general and "Chamaeleo dilepis - complex" in particular harbors cryptic diversity (Macey & al. 2008; Main 2018, Main & al. 2018; Tilbury 2018; Ullenbruch & al. 2007). 

The whole complex is in need of a deep revision, until then, the status of individual forms is to be considered as tentative. Nevertheless, the investigation of the material referred to Chamaeleo roperi Boulenger, 1890 and Chamaeleo martensi Mertens, 1964 revealed an inconsistency, which needs to be rectified regardless. The evidence of specific status of Chamaeleo ruspolii Boettger, 1893 has been provided by Spawls & al. (2023) and Nečas & al. (2025). 

Status of Chamaeleo roperi Boulenger, 1890

Chamaeleon roperi was described originally as a separate species treated as a subspecies or species subsequently (after Glaw 2015):

1890 Chamaeleon roperi Boulenger, Proc. zool. Soc. London, 1890: 85; pl. 8, fig. 4. – Type locality: Kilifi, north of Mombasa, Kenya. – Syntypes: BMNH 1946.8.22.1 – 2 (2 specimens).

1902 Chamaeleon dilepis var. roperi – Werner, Zool. Jb., Syst., 15: 343.

1911 Chamaeleon dilepis roperi – Werner, Das Tierreich, 27: 13.


1966 Chamaeleo dilepis roperi – Mertens, Das Tierreich, 83: 13.


1997 Chamaeleo (Chamaeleo) dilepis roperi – Klaver & Böhme, Das Tierreich, 112: 34.

2010 Chamaeleo dilepis "roperi form" – Tilbury, Chameleons of Africa, 493.

2015 Chamaeleo dilepis roperi – Glaw, Vertebrate Zoology, 65(2):167–246.

2018 Chamaeleo dilepis roperi – Main & al., African Zoology, 53:1: 11–16.

2018 Chamaeleo dilepis "roperi form" – Tilbury, Chameleons of Africa, 643.

I take the liberty to set up a hypothesis which is to be proven with further detailed studies: The "Chamaeleo cf. roperi phenotype", defined by the diastema between the occipital lobes represents in fact the original coastal chameleon, as identified by Boulenger (1890) and described as Chamaeleon roperi, while the "Chamaeleo dilepis phenotype" with occipital lobes joining at the top of the casque is typical Chamaeleo dilepis. Their distributional patters were shaped by their preference of the inhabited biotopes, defined mainly by climate and vegetation.

The Indian Ocean significantly influences the climate of the coastal regions of Kenya and Tanzania, particularly through its impact on rainfall patterns and temperature regulation.

• Short Rains (October–December): The Indian Ocean plays a crucial role in the variability of the short rains (OND) along the East African coast. Sea Surface Temperature (SST) anomalies in the Indian Ocean, especially in the western part, are strongly correlated with rainfall anomalies during this season. Positive SST anomalies in the western Indian Ocean lead to increased rainfall over the coastal regions of Kenya and Tanzania. Conversely, negative SST anomalies can result in reduced rainfall and drought conditions (Behera & al. 2005).

• Long Rains (March–May): While the Indian Ocean's influence on the long rains (MAM) is less pronounced than on the short rains, it still plays a role in modulating rainfall patterns. The interannual variability of the long rains is influenced by a combination of factors, including SSTs in the Indian Ocean and the El Niño-Southern Oscillation (ENSO) phenomenon (Ummenhofer & Meehl, 2007).

• Moderating Effects on Temperature Regulation: The Indian Ocean exerts a moderating effect on coastal temperatures, leading to milder temperatures compared to inland areas. The ocean's heat capacity helps to buffer temperature extremes, resulting in cooler summers and warmer winters along the coast (Schneider, 1996).

• Sea Breezes Effects on Temperature Regulation: During the day, the land heats up faster than the ocean, creating a temperature difference that generates sea breezes. These breezes bring cooler, moist air from the ocean to the coast, providing a cooling effect and contributing to higher humidity levels (Simpson, 1994).

The influence of the Indian Ocean on the vegetation of the coastal regions of Kenya and Tanzania is significant, primarily through its impact on rainfall patterns and temperature regulation, as shown above. Therefore, the coast consists mainly of three natural vegetation zones:

• "Mangrove" restricted to several areas along the coast with shallow tidal zones. Not inhabited long-term by any chameleons as they can not reproduce in inundated saline or brackish areas.

• "Savanah-Like Communities Derived from Forest" with scattered remnants of "Coastal Thicket Forests" (e.g. the Arabuko-Sokoke Forest Reserve and National Park), building relatively narrow belt of just several kilometres wide coastal-climate influenced natural vegetation. They were drastically reduced by human activities on the course of many centuries, deforested and modified to urban areas, farmland, plantations or wasted and aridized. The remnants of the coastal forest thickets are inhabited primarily by Chamaeleo roperi.

• "Dry Bushland and Thicket" - a vast area inland of the previous ones. Due to the deforestation and aridisation, either human made biotopes such as farmland and plantations or this type of vegetation replaced the above vegetation type and sometimes reaches up to the coastline. This vegetation zone is primarily inhabited by Chamaeleo dilepis, while its distributional patterns are heavily influenced by the level of subterranean and surface water, enabling them to reproduce - thus they are usually found along the riverbeds and lakes (Nečas 1999, 2020; Tilbury 2018).

Logically, the question arises: Why are both phenotypes/species found on/along the coast? The explanation lies in the patterns commented above: very likely, the original coastal forest, inhabited by Chamaeleo roperi, was replaced by cultural landscape and due to deforestation, it became more arid and hot, thus enabling to Chamaeleo dilepis, which thrives in these biotopes, to colonize the deforested areas.

From the all above analysis, it is justified (at least preliminarily, before genetic studies are conducted and more reliable material collected) to raise Chamaeleo roperi from the subspecific ranking and refer the Kenyan and Tanzanian coastal populations, showing the occipital lobes diastema, to Chamaeleo roperi as a separate species, obviously closely related to Chamaeleo dilepis and still being a part of the "Chamaeleo dilepis - complex".

The populations, previously referred to as Chamaeleo dilepis roperi (with the exception of the type series and some scattered reports of aberrant specimens), significantly differ from nominotypical Chamaeleo dilepis and represent a separate species, as clearly demonstrated above. As the type specimens are clearly identified and exist, and neither any synonym of Chamaeleo roperi, nor any synonym of Chamaeleo dilepis referable to the defined highland form is available, there is an obvious need for formal description of the highland form, separating it from the nominotypical Chamaeleo dilepis and all other forms of the "Chamaeleo dilepis - complex".

Description of new species

Chamaeleo incognitus, sp.n.

The Montane Flap-Necked Chameleon

Holotype: NMK L4091/1, male, collected by Joash Nyamache on 13. february 2018

Paratype: NMK L4091/2, female, same data as holotype

Type locality: East of Meru, Kenya (0°06'46'' N; 37°42'01'' E; 1,381 m a.s.l.). Farmland within the shambas in suburbs of Meru, along the way to Nyambene Hills.

Diagnosis:

A small member of the "Chamaeleo dilepis - complex", with the combination of features as below:

• reaching maximum head and body length 140mm in females and 100mm in males,
• with an indistinct lateral crest caudo-dorsally,
• with small, vestigial and non-functional occipital flaps separated from each other on the top of the casque and above the neck by a diastema,
• with deep orange, brick red, crimson to purple interstitial skin in the gular grooves,
• lacking tarsal spurs in males and females,
• with well developed temporal glands,
• hemipenis with one pair of apical and two pairs of sulcal rotulae,
• fully grown females about 40% bigger than males.

Description of the type:

General: A typical chameleon of small size, equipped with all typical chameleon features like chamaeleodactylous feet, prehensile tail, independently moving eyes in lid turrets, long prehensile tail, skin capable of color change.

Head: The head with typical rough crests consisting of heavily enlarged warty or pointed scales. The lateral crest becomes faint to indistinct towards the tip of the casque behind the level of eyeholes. The occipital lobes are minute, covered with scales of same size as surrounding head parts, they do not touch each other being widely separated above the neck by a clear gap. A fully functional temporal gland present, with lumen partly coloured black.

Extremities: Extremities thin, chamaeleodactylous, with no tarsal spur.

Scalation: All head, body and extremities are scaled homogeneously. The scales on flanks are aggregated usually in groups of four. The dorsal crest is well developed, consisting of a single row of conical scales of a double the size at the base compared to surrounding scales, the highest conical scales slightly higher than wide at the base, are situated in the first 3/5 of the body, then consecutively getting smaller until becoming indistinct at second half of the tail. The gular crest consisting of conical pointed scales along the midventral line starting just under the chin and becoming highest between the level of the orbit and sternum, where it consists of high conical pointed scales up to twice as high as they are wide at the base. It continues caudally as a white, lower ventral crest on the belly, disappearing just in front of the cloacal opening.

Hemipenis: The truncus is deeply calyculated. The Apex with two large serrated rotullae, two pairs of serrated but smaller rotullae along the sulcus spermaticus.

Fig. 13, 14 & 15: Hemipenis of the type of Chamaeleo incognitus, sp.n. Photo: P. Nečas

Coloration and pattern: Uniform green, or light green with a pattern of brownish crossbars and dots, sometimes light brown to brown with or without pattern. Quite constantly, white markings are found in form of lines or stripes on three places: on the posterior half of upper and lower lips, a continuous line from axilla to groin and two spots on a hypothetical longitudinal parallel line above the one before: one just behind the head at the height of lower margin of the occipital lobe and one in about 2/5 of the body length on the flank. These markings are always distinct and can change color to grey, brown to black. The dorsal crest is of same color as surrounding skin, gular and ventral crests white. The interstitial skin of gular grooves are of crimson colour.

Coloration in formaldehyde: uniformly bluish grey.

Variation in paratype: 

The paratype is a female, all features are same as in the male, the head is slightly relatively smaller and the tail is slightly less than half of total length, while in the type, it is slightly more.

Derivatio nominis: 

The specific epithet "incognitus" is a Latin adjective meaning "unknown, unidentified" referring to its long history of being actually unknown though known under wrong names. In accordance with the masculine grammatical gender of the genus Chamaeleo, it is used in the masculine form. 

Distribution:

This species is confined to the Kenyan highlands from Nairobi, around Mt. Kenya and at foothills of the Aberdare Mountains.  Preliminarily, all known populations of the highland members of the "Chamaeleo dilepis - complex" of Kenya and Tanzania, with so far confirmed occurrence on the following mountains and areas, always in the lower afromontane forest zone, often degraded by agricultural activities, can be referred to this species, until further, especially genetic studies, show otherwise. 

Kenya: Aberdare Mountains (Kinangop plain), Loita Hills (Entasikira), Machakos, Mathews Range (Mount Warges), Mount Kenya (East slopes: Embu, Chogoria, Meru, West slopes: Laikipia), Nyambeni Hills (Kigochwa, Maua), Ol Doniyo Orok (Namanga Hill), Taita Hills (Wundanyi, Sagalla Hill, Mount Mbololo), Vicinity of Nairobi (N of Juja, Karen).

Tanzania: Kilimanjaro, Mount Hanang, Mount Kwaraha, Mount Longido, Mount Meru, South & North Pare Mountains, Udzungwa Mountains.

After this paper is published, more precise identification of individual distribution of this taxon should be done and possibly, other mountain ranges will be added to the list. Other suspect mountains out of the above defined range, such as Gabon, Angola, Uganda, Tanzania and DR Congo, as presented by Glaw (2015) and Tilbury (2010, 2018) need revision, as they either can represent the here described species or represent different taxa including aberrant specimens of Chamaeleo dilepis showing similar characters.

Fig. 19, 20 & 21: Occipital lobe diastema of Chamaeleo incognitus, sp.n., all Meru, Kenya. Photo: P. Nečas

Sympatric chameleon species, with indication of syntopy (ST):

Aberdare Mountains: Trioceros hoehnelii, Trioceros kinangopensis, Trioceros jacksonii (ST);

Kilimanjaro: Trioceros sternfeldi, Kinyongia tavetana (ST);

Loita Hills: Trioceros cf. sternfeldi (ST);

Machakos: Trioceros jacksonii (ST);

Mathews Range: Trioceros sp. (documented undescribed species), Chamaeleo gracilis;

Mount Hanang: Trioceros hanangensis, Kinyongia uthmoelleri ;

Mount Kenya (East slopes): Trioceros hoehnelii, Trioceros schubotzi, Trioceros jacksonii (ST), Kinyongia excubitor (ST);

Mount Meru: Trioceros sternfeldi, Trioceros merumontanus, Kinyongia tavetana (ST);

Mount Longido: Trioceros bitaeniatus (ST), Trioceros sternfeldi (ST), Kinyongia tavetana (ST);

Nairobi (Vicinity of): Trioceros jacksonii (ST), Trioceros hoehnelii (ST);

Nyambene Hills: Trioceros jacksonii (ST), Kinyongia excubitor (ST), Rieppeleon kerstenii;

Ol Doniyo Orok: Chamaeleo dilepis, Trioceros sp. (documented undescribed species);

South & North Pare Mountains: Kinyongia artytor (ST), undescribed Kinyongia cf. tavetana (ST), Rhampholeon viridis;

Taita Hills: Kinyongia boehmei (ST); Chamaeleo dilepis, Rieppeleon kerstenii.

Compilation is based on own data, Bwong & al. (2025), Glaw (2015), Malonza (2023), Spawls & Rottich (1997), Tilbury (2018).

Status of Chamaeleo martensi Mertens, 1964

During the survey of Chamaeleo dilepis and Chamaeleo roperi, additional specimens of the very rare Chamaeleo martensi were examined (i.a. Nečas 2025c). Examination of them, along with photographic evidence, reveals significant morphological distinctions when compared to Chamaeleo dilepis.

Pemba Island is believed to have separated from the mainland earlier than Zanzibar. Pemba's separation likely occurred during the Miocene Epoch, approximately 10 million years ago. In contrast, Zanzibar (Unguja) is thought to have separated from the mainland during the Pliocene Epoch, around 5.3 to 2.6 million years ago (Pickford 2008). Its geological isolation and climate contribute to high endemism:

• Aloe pembana (Asphodelaceae) (Pemba Aloe),

• Dypsis pembana (Arecaceae) (Pemba Palm).

Endemic Animal Species e.g.:

• Pteropus voeltzkowi (Aves: Pteropodidae) (Pemba Flying Fox): (Mickleburgh & al., 1992),

• Treron pembaensis (Aves: Columbidae) (Pemba Green-Pigeon): (Moreau, 1944),

• Cinnyris pembae (Aves: Nectariniidae) (Pemba Sunbird): (Fry & al., 2000),

• Otus pembaensis (Aves: Strigidae) (Pemba Scops-Owl): (Stevenson & Fanshawe, 2002).

According to Main (2019), diversification within the Chamaeleo dilepis took place from the late Miocene to the Pliocene. It means, if the Pemba populations were separated from the mainland around 10 million years ago, the speciation should have taken place within this period or even before, if their ancestors have not been drifted there later e.g. by sea on logs. 

The high level of endemism and long separation of the Pemba island from the African mainland supports the possibility of the existence of an endemic chameleon species. Its distinction and specific status is also justified by its unique morphology which is present at a level which is used for separating other chameleon species with similar morphology to Chamaeleo dilepis from it itself, such as Chamaeleo ruspolii, Chamaeleo gracilis, Chamaeleo monachus. The molecular data indicating the speciation within the "Chamaeleo dilepis - complex" fall within the time period, when Pemba was already separated from the mainland Africa. Therefore, Chamaeleo martensi should be considered a valid species. Its status and relationship within the "Chamaeleo dilepis - complex" or even outside of it will hopefully be delivered by future phylogenetic studies.

Discussion

According to Glaw (2015) and Tilbury (2010, 2018), the form, mentioned by them, as Chamaeleo dilepis roperi or by Tilbury (2018) taxonomically irrelevantly mentioned as Chamaeleo dilepis "roperi form" (there is, according to the ICZN no taxonomical category called "form" in this form of writing) have been so far reported besides of Kenya and Tanzania, also from Gabon, Angola, Uganda, and DR Congo. The four latter countries are in need to be confirmed as a range of Chamaeleo incognitus by further studies and are to be preliminarily excluded from the list, as the records can be based on misidentified or aberrant specimens.

Ullenbruch & al. (2007) used material referred to Chamaeleo roperi, which did not originate from the type locality (Kilifi on the Kenyan Coast) or its vicinity but from Mount Kwaraha and Mount Hanang in Tanzania), which is not only geographically quite distant (750km resp. 600km air distance) but also it represents a completely different climatic zone due to the altitude (highland montane habitats at over 2000m alt versus the coastal climate at sea level). Their material can be treated with caution, as it definitely does not refer to Chamaeleo roperi but probably to Chamaeleo incognitus, or some undescribed other form. Mount Kwaraha is a granite inselberg that rises to an elevation of 2,415 meters (7,923 feet). The mountain features mist forests above 1,800 meters (5,900 feet). The Ufiome Forest Reserve encompasses 54.36 square kilometers (20.99 square miles) of the mountain. Mount Hanang is a dormant stratovolcano, reaching an elevation of 3,420 meters (11,220 feet). The Mount Hanang Nature Forest Reserve covers an area of 58.66 square kilometers (22.65 square miles), protects an enclave of evergreen montane forest on the mountain's higher slopes. Between 2,000 and 2,700 meters (6,600 and 8,900 feet) elevation, evergreen montane forests dominate the mountain's wetter eastern and southern slopes, while the drier western and northern slopes are home to dry montane evergreen forests with bushland and grassland on the ridges.

In Chamaeleo dilepis namely, its range is so big that very likely, further investigations will reveal more cryptic taxa (Main & al. 2018; Ullenbruch & al 2007; Tilbury 2010, 2018). Chamaeleo dilepis is on vast majority of the inhabited territory the only chameleon species and does not as a rule occur syntopically with other species. In cases, where it happens, it climbs around the deforested areas to reach even the afromontane forest margin and as a pioneering species it touches the indigenous populations of the chameleons there, as e.g. in the East Usambara mountains (K. matschiei, vosseleri, tenuis; Trioceros deremensis, melleri; Rhampholeon spinosus, temporalis; Rieppeleon brevicaudatus) or at Magombera Forest (Kinyongia magomberae and Rieppeleon brevicaudatus) or in the Udzungwa Mountains (e.g. Trioceros incornutus, laterispinis, werneri; Kinyongia msuyae, oxyrhina; Rhampholeon moyeri), all Tanzania (personal observations). It is the exception of the rule but corrected by strong niche partitioning: Chamaeleo dilepis in the deforested secondary biotopes and the indigenous species tied to the forest and only marginally penetrating the deforested areas. 

This fact put evolutionarily also no pressure for character displacement (sensu Rand, 1963 and Necas 1999) on the morphology of Chamaeleo dilepis, which, along with a rather primitive external expression (lacking heterogeneous scallation, high helmets, cranial protuberances) remains the species rather uniform, with no need to diversify nor stabilize the external appearance for the benefit of interspecific differentiation morphologically, as they have simply with no one to compete and to differentiate against. The end result is a relatively uniform appearance across vast territories plus certain variability and instability in the development of some features, such as the form of the occipital lobes, which are the only exception in the presence of cranial protuberances. This also makes the assessment of the old museum material problematic, as differences seem to be minute or absent or related to intraspecific variability, the conclusion, which Tilbury (2010, 2018) presented as his general conclusion in inability to separate the individual forms and populations and to see any logic in the distributional patterns. In contrast, Chamaeleo incognitus is exposed to a clear pressure of character displacement, because it occurs sympatrically with Trioceros jacksonii xantholophus, Trioceros hoehnelii; Kinyongia excubitor at and around its type locality.

Some of the recent indications, however, clearly show, that some forms are distinct and it is practical rather to consider them a separate species than to throw them into the synonymy or handle them as non-existing taxonomic categories "forms" (sensu Tilbury 2010, 2018), especially for the purpose of their practical identification in the field and for the purpose of the conservation of them and their biotopes, and for the purpose of CITES.

The term diastema, frequently used in this publication, originates from the Greek word "διάστημα" (diástēma), which means "interval" or "space." The root "διά" (diá) translates to "through" or "between," and "στήμα" (stēma) refers to "standing" or "interval." The word was adopted into Latin as "diastema," maintaining the same meaning of a gap or space.

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Appendix: Vegetation Map of Kenya and Tanzania 

Nečas, P. (2025): The New Mysterious Highland Flap-Necked Chameleons from East Africa, with remarks on the status of Chamaeleo roperi BOULENGER, 1890 and Chamaeleo martensi MERTENS, 1964 (Sauria: Chamaeleonidae). Archaius 2(1): 7

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