Suárez
42
ANARTIA
Publicación del Museo de Biología de la Universidad del Zulia
ISSN 1315-642X (impresa) / ISSN 2665-0347 (digital)
Anartia, 33 (diciembre 2021): 42-54
Freshwater crabs from the highlands of the Venezuelan
Guayana
Cangrejos dulceacuícolas de las tierras altas de la Guayana venezolana
Héctor Suárez A.
Centro de Ecología, Instituto Venezolano de Investigaciones Científicas (IVIC),
Apartado Postal 20632, Caracas, 1020-A, Venezuela.
Correspondence: hsuarez@ivic.gob.ve
(Received: 15-07-2021 /Accepted: 05-10-2021/ Online: 31-01-2022)
ABSTRACT
Neotropical freshwater crabs have a wide distribution range from southern Mexico to Peru, including the entire Amazon
basin and the Guianas. Among them, highland species of the genus Microthelphusa Pretzmann, 1968, have a very peculiar
biogeography. eir distribution is insular and discontinuous, presenting considerable separation between them. Twelve
species are found south of the Orinoco River, of which six are found in the Venezuelan Guayana, and of these, ve are
endemic to the highlands of the tepuis. In this paper I attempt to explain the distribution of the species of Microthelphusa
and their occurrence in the upper elevations of the tepuis.
Keywords: biogeography, freshwater crabs, insular distribution, Microthelphusa, Neotropics, taxon cycle, tepuis.
RESUMEN
Los cangrejos de agua dulce neotropicales tienen un amplio rango de distribución desde el sur de México hasta Perú,
incluida toda la cuenca del Amazonas y las Guayanas. Entre ellos, las especies de grandes altitudes del género Microthel-
phusa Pretzmann, 1968, tienen una biogeografía muy peculiar. Su distribución es insular y discontinua, presentando una
separación considerable entre ellos. Doce especies se encuentran al sur del río Orinoco, de las cuales seis se encuentran en
la Guayana venezolana, y de estas, cinco son endémicas del altiplano de los tepuyes. En este artículo intento explicar la dis-
tribución de las especies de Microthelphusa y su presencia en las elevaciones superiores de los tepuyes.
Palabras clave: biogeografía, cangrejos dulceacuícolas, ciclo de taxones, distribución insular, Microthelphusa, Neotrópico,
tepuyes.
INTRODUCTION
e Amazon basin supports the greatest terrestrial
biodiversity (Wilson 1992, Webb 1995). But why this
singularity? Largely it is due to the complexity of the geo-
logical changes that the South American continent has
undergone since its separation from Pangea during the
Lower Cretaceous and its gradual shi to its present posi-
tion (Shell de Venezuela & Creole Petroleum Corporation
1964, Gayet et al. 1992, Ruban et al. 2009). One of those
geological features that characterize South America are
the Andes, the world’s longest mountain range, which is
the product of the slow subduction of the Nazca Plate be-
neath the South American plate from the Late Cretaceous
to the present. is has led to a gradual and dierentiated
upli of the mountain ranges that concluded at the end of
the Miocene with the emergence of the Serranía de Perijá
and the Venezuelan Andes. is process diers markedly
from the uprising of other mountain systems such as the
Alps, the Himalayas and the Rockies, which are the prod-
uct of large clashes of continental masses (Weeks 1956,
Harrington 1962, Ricardi 1987, Kroonenberg et al. 1990,
Highland crabs of the Venezuelan Guayana
43
Andriessen et al. 1993, Rossetti et al. 2005, Jaimes & de
Freitas 2006, Ramos & Moreno 2006, Cardona Molina et
al. 2006, Ramon & Rosero 2006, Cortés et al. 2006, Silva
Tamayo et al. 2008, Leier et al. 2013).
Another important feature is that the separation of
South America from Africa was a slow process that ini-
tially allowed the migration of species between the two
continents for a long period and the slow formation of
the South Atlantic (Iturralde-Vinent 2003, Allibon et al.
2008, Dentzien-Dias et al. 2008, Brookeld et al. 2009,
Woodburne 2010, Teixeira et al. 2019). At the end of this
separation, the South American continent is positioned in
a stable climatological zone, although the creation of the
Atlantic produced great changes in the global climate and
in the patterns of marine currents. From this moment on,
the continent was subject to regressions and marine trans-
gressions that at dierent times were modulated by the
presence of the great continental cratons and the Andes.
During the periods of marine transgressions the emerged
lands acted as islands and “laboratories” for the diversi-
cation of species, which were dispersed and mixed during
the marine regressions. e presence of the epicontinental
seas had an overwhelming impact on the diversity of the
continent’s aquatic fauna, represented by a large number of
species of sh, mammals, mollusks and crustaceans of di-
rect marine origin, currently found in the Amazon and the
eastern slopes of South America. is phenomenon is very
interesting because as the Andes were lied by pulses, they
were framing the epicontinental sea, at rst allowing con-
nections between it and the Pacic, the Proto-Caribbean
and the South Atlantic, and then gradually closing these
portals, which created an immense estuary in which the
marine forms were slowly evolving to their current fresh-
water forms. e last growth pulse of the Andes at the
end of the Miocene produced a dramatic change in this
immense estuary, as it changed the direction of the ow
of the Proto-Amazonas-Orinoco and gradually guided
them to their current mouths. is drained the estuarine
lake and created the current Amazon and Orinoco River
basins (Haq et al. 1987, Habib & Miller 1989, Lundberg
1992, Hoorn 1993, 1994, Rasanen 1995, Monsch 1998,
Rull 1999, Hamilton et al. 2001, Schram 2001, Feldmann
2003, Bush et al. 2004, Albert et al. 2006, Anderson et al.
2006, Cunha-Ribeiro 2006, Cozzuol 2006, Feijó-Ramos
2006, Hoorn & Vonhof 2006, Hulka et al. 2006, Kaan-
dorp et al. 2006, Kay & Cozzuol 2006, Lovejoy et al. 2006,
Muñoz-Torres et al. 2006, Rebata et al. 2006, Wesselingh
& Macsotay 2006, Westaway 2006, Almeida-Filho &
Miranda 2007, Latrubesse et al. 2007, Flynn et al. 2008,
Jasper et al. 2008, Mantelatto et al. 2008, Bond-Buckup
et al. 2010, Leonhardt & Lorscheitter 2010, Shephard et
al. 2010, Anger 2013, Lasso et al. 2013, Wade 2013, 2017,
Cumberlidge et al. 2014, Perkins 2014, Lovejoy 2017,
Posada-Swaord 2017, Davis et al. 2018).
e importance of these geological phenomena that
I have tried to summarize here can be easily modeled
through the brachyuran decapod crustaceans, of which
there is a more or less well documented fossil record since
the end of the Jurassic (Ortmann 1902, Stevcic 1971, Cis-
ne 1974, Rodríguez & Díaz 1977, Cracra 1988, Vega &
Felman 1991, Malabarba et al. 1998, Von Sternberg et al.
1999, Feldmann & Schweitzer 2006, Limarino & Spalletti
2006, Fabbrin Pires & Guerra Sommer 2009, Candeiro &
Rich 2010, Hoorn & Wesselingh 2010, Haug et al. 2015,
Klaus et al. 2017).
FRESHWATER CRABS OF SOUTH AMERICA
AND THEIR PECULIAR DISTRIBUTION
IN THE HIGHLANDS
Among the decapod crustaceans, the Brachyura is
the most successful lineage, possessing more than seven
thousand species with a great variety of morphotypes.
ey have managed to conquer almost every habitat in
the world, from underwater volcanic vents on the oce-
anic ridges to the top of mountains at 2,000m above sea
level. e vast majority of species are marine, but about
1,300 are freshwater species and some of these are semi-
terrestrial (Haug et al. 2015). In the Neotropics we nd
two families of freshwater crabs, the Trichodactylidae,
restricted almost exclusively to the aquatic environment
(Díaz & Rodríguez 1977), although there is evidence that
they can carry out terrestrial migrations under heavy rains.
ese have an altitudinal distribution that goes from ap-
proximately 0 m a.s.l. to 550 m a.s.l. ey are distributed
in the coastal plains of the Guianas and Brazil, in the great
uvial plains of the Amazon, the Orinoco, Paraguay and
Paraná and in the separate basins of Magdalena and Lake
Maracaibo. Two genera are also found in southern Mexico
(Rodríguez 1992).
e other family, Pseudothelphusidae, represents an
evolutionary leap for the conquest of terrestrial environ-
ment, developing pseudolungs to take the atmospheric air,
transforming their gills to recover sodium and potassium.
ey have a dense cover of hairs in their legs and in the
gill region to allow the absorption of water from the sur-
rounding air passing it to the respiratory chamber. In ad-
dition, they have direct development inside the egg, and
exhibit parental care.
Although these are great evolutionary achievements,
it is still far from possible to consider these organisms as
terrestrial, since their cephalothorax is still too perme-
Suárez
44
able and they dry out easily if they are not in contact with
very humid surfaces. eir altitudinal distribution ranges
from 400 m a.s.l., up to 2,000 m a.s.l., and extends from
the State of Sonora in Mexico to the outskirts of Lima in
Peru, including the Great Antilles (except Jamaica) and
the Guianas. e family is composed of two subfamilies,
Epilobocerinae and Pseudothelphusinae.
Epilobocerinae is the most primitive and has only one
genus Epilobocera Stimpson, 1860, found in the Greater
Antilles. e second, Pseudothelphusinae, with ve tribes:
Strengerianini, with four genera: Strengeriana Pretzmann,
1971, Chaceus Pretzmann, 1965, Martiana Rodríguez,
1980 and Phallangothelphusa Pretzmann, 1965, dis-
tributed in northern Colombia. Hypolobocerini, with
eleven genera: Hypolobocera Ortmann, 1897, Moritschus
Pretzmann, 1965, Neostrengeria Pretzmann, 1965, Pty-
chophallus Smalley, 1964, Phrygiopillus Smalley 1970,
Spirothelphusa Pretzmann, 1965, Camptophallus Smalley,
1965, Elsalvadoria Bott, 1967, Lobithelphusa Rodríguez,
1982, Raddaus Pretzmann, 1965 and Achlidon Smalley,
1964, distributed through the Andes to Peru. Potamo-
carcinini, with four genera: Potamocarcinus H. Milne-Ed-
wards, 1853, Typhlopseudothelphusa Rioja, 1952, Odonto-
thelphusa Rodríguez, 1982 and Allacanthos Smalley, 1964,
that are distributed across the Atlantic coast from Central
America to Mexico (Rodríguez 1982). Pseudothelphusini,
with three genera: Ehecatusa Ng & Low, 2010 (= Epithel-
phusa Rodríguez & Smalley, 1970), Tehuana Rodríguez
& Smalley, 1969 and Pseudothelphusa Saussure, 1857, dis-
tributed from the Atlantic coast of Mexico, crossing to the
Pacic and extending to the Sierra Madre in Sonora; and
Kingsleyini, with 10 genera: Eudaniela Pretzmann, 1971,
Rodriguezus Campos & Magalhães, 2005, Microthelphusa
Pretzmann, 1968, Neopseudothelphusa Pretzmann, 1965,
Kingsleya Ortmann, 1897, Orthothelphusa Rodríguez,
1980, Oedothelphusa Rodríguez, 1980, Prionothelphusa
Rodriguez, 1980, Fredius Pretzmann, 1967 and Guinotia
Pretzmann, 1965, distributed from the Venezuelan Andes,
passing through the Cordillera de la Costa to Trinidad and
Tobago then turning to the Guiana Shield to the le mar-
gin of the Amazon (Rodríguez 1982, Campos et al. 2002,
Campos & Magalhães 2004, Suárez 2006, 2013, Magal-
hães & Pereira 2007, Cumberlidge et al. 2009, Magalhães,
2009, Pereira et al. 2009).
e presence of both families on the continent is older
than it had previously been considered. If we observe the
new models for the Caribbean geologic formation (Me-
schede & Frisch 1998; Iturralde-Vinent 2003; Klaus et al.
2017) that show how the Greater Antilles were part of
Pangea 160 Ma, and considering that the oldest species
are in the external limit of the distribution of the family
(Rapoport 1975), we can assume that the Epilobocerinae
were already distributed in the north of South America in
the middle of the Jurassic and could be considered living
fossils. We now know that brachyuran megalope fossils
similar to the present ones, already inhabited the oceans
150 Ma (Haug et al. 2014). is might explain the dis-
junct distribution of the subfamily in the Greater Antilles.
e oldest known fossil record of a Trichodactylidae to
date is Sylviocarcinus piriformis (Pretzmann, 1968), a spe-
cies which has currently a disjunct distribution between
the Lake Maracaibo Basin, the Cesar River Valley and the
Magdalena River Valley sector between Puerto Boyacá and
the Gualanday River (Rodríguez 1997, Souza-Carvalho et
al. 2017, Klaus et al. 2017). is living fossil is possible evi-
dence of the existence of an opening that allowed the Pro-
to-Amazonas-Orinoco to ow towards the Pacic, which
was closed at the end of the Miocene with the rise of the
Sierra de Perijá and the Venezuelan Andes. is geologi-
cal event also promoted the upli of the Coastal Range of
Venezuela and the subsequent colonization of Pseudothel-
phusidae species along this mountains system (Stephan et
al. 1990, Coates et al. 1992, Collins et al. 1996, Murdock
et al. 1997, Haug & Tiedemann 1998, Haug et al. 2001,
Restrepo & López 2008, Martínez et al. 2010, Wood-
burne 2010).
INSULAR DISTRIBUTION
OF PSEUDOTHELPHUSID CRABS
OF THE PANTEPUI
One of the genera from south of the Orinoco that colo-
nized these new spaces since the late Miocene, beginning
in the Andean foothills, is Microthelphusa Pretzmann,
1968. It has a wide distribution range, from the Cordillera
de Mérida (Venezuela) through the Cordillera de la Costa
to Trinidad, here its distribution suffers a disjunction and
reappears in the southern margin of the Orinoco River,
from the Venezuelan Guayana, the Venezuelan Amazon,
Guyana and Surinam to the Amazonas State of Brazil
(Fig.1). Altitudinal distribution of the genus ranges from
500 m a.s.l. to 2,000 m a.s.l. in the north, and from 400m
a.s.l. to 1,600 m a.s.l. in the southern margin of the Ori-
noco, which confers an insular distribution to the spe-
cies. In addition, Microthelphusa species are associated in
the base of their altitudinal distribution with other genus
of greater size that in the case of the species of the north
range is Rodriguezus Campos & Magalhães, 2004 and in
those that are in the southern margin of the Orinoco is
Fredius Pretzmann, 1967. ese genera are of large size
(between 5 and 12 cm of cephalothorax width in the case
of Rodriguezus and between 4 and 9 cm of cephalothorax
Highland crabs of the Venezuelan Guayana
45
width in the case of Fredius), compared with Microthel-
phusa (whose width of cephalothorax oscillates between
1.5 and 3 cm) (Fig. 2).
Figure 1 shows the distribution range of species of Mi-
crothelphusa in the northern border of Venezuela, between
the Andes to Trinidad and the Orinoco to the Amazon
River, from the high savannas of Surinam and Guyana, to
the Tepuis of Venezuela (in Amazonas and Bolívar states)
and Serra do Aracá in the state of Amazonas of Brazil.
e lowest altitude species in this group is Microthelphusa
furcifer Pedraza & Tavares, 2014 (440 m a.s.l.), followed
by M. roraimensis Suárez, 2015 (900 m a.s.l.) (Fig. 2A),
M. wymani (Rathbun, 1905) (506 m a.s.l.), M. aracamu-
niensis Suárez, 2015 (1,000-1,500 m a.s.l.) (Fig. 2C), M.
rodriguezi Pretzmann, 1968 (800 to 950 m a.s.l.), M. bo-
livari Rodríguez 1980 (1,000 m a.s.l.), M. meansi Cum-
berlidge, 2007 (1,135 m a.s.l.) and M. lipkey Magalhães,
2010 (1,000-1,200 m a.s.l.), M. guaquinimaensis Suárez,
2015 (1,380-1,400 m a.s.l.) (Fig. 2B), M. marahuacaensis
Suárez, 2015 (1,500 m a.s.l.) (Fig. 2D) and M. maiguali-
daensis Suárez, 2015 (1,500 m a.s.l.) (Fig. 2E) (Table 1).
All these species are found within what was named Pan-
tepui, by Mayr & Phelps, Jr (1955).
“e sandstone plateaus located in the Bolivar and
Amazonas states of Venezuela and in the border regions of
Guyana, Suriname, Brazil and Colombia”. is denition
has an explicit geographic criterion related to the exten-
sion in surface and height, as well as an implicit biological
criterion, referring to the conditions of life in the area in
question (Costa et al. 2014a). Subsequently, several re-
searchers oered dierent interpretations of the term Pan-
tepui (Müller 1973, Hoogmoed 1979, Steyermark 1979,
Brown 1987, Neild 1996, 2008), which departed from the
original concept. To clearly dene it from the geographi-
cal and biological point of view Huber (1987), describes it
as: “e Pantepui biogeographic province, which is part of
the Guiana Region, includes the set of orographic ecosys-
tems developed in the tabular mountains (Tepuis), of the
Figure 1. Map of the distribution area of the genus Microthelphusa Pretzmann, 1968.
Suárez
46
Figure 2. Dorsal view of the cephalothorax and habitus of several species of Microthelphusa Pretzmann, 1968, from the highlands of
the Venezuelan tepuis, present in the Crustacean Collection of IVIC: A. M. roraimensis; B. M. guaiquinimaensis; C. M. aracamunien-
sis; D. M. marahuacaensis; E. M. maigualidaensis.
Highland crabs of the Venezuelan Guayana
47
Roraima Formation of the Guiana Shield, extending from
1,200-1,500 to 3,045 m a.s.l. It is a tropical orobiome in
the sense of Walter (1976), the “orobioma tepuyano”, in
which are included all the ecosystems of the upper slopes
and summits of the Tepuis, located in the meso- and sub-
thermal altitudinal tropical oors”. Costa et al. (2014a),
report the existence of more than y tepuis, and present
a map of their distribution and of the mountain massifs
that reach at least 1,500 m a.s.l., in the Guiana shield.
ese tabular mountains have fascinated researchers
and the imagination of the general public for centuries
since Sir Walter Raleigh described them in his notes “e
discovery of the great, rich and beautiful Empire of Guay-
ana”. For Sir Arthur Conan Doyle (1912), in his ctional
novel “e lost World”, these mountains of vertical walls
were the reservoir of extinct fauna and ora of the Juras-
sic (Schubert 1993). However, radio carbon studies car-
ried out on the peatlands of the Venezuelan tepuis show
that they are between 8,000 and 9,000 years old before the
present (Schubert & Fritz 1985, Schubert 1986, 1986a,
Schubert et al. 1994). erefore, it is inferred that the
present fauna and ora of the tepuis have only developed
since the uaternary (Steyermark 1979).
e majority of the species that cohabit in these moun-
tains are endemic of the tops where they occur and show
an insular distribution, in addition they are organisms
adapted to sudden changes of temperature, low nutrients
availability, and acid waters, among other factors. Why a
crab rises to these high peaks in which calcium availability
in the water is not enough to regenerate their cephalotho-
rax? eir body size decreases to facilitate oxygen uptake,
and they develop special strategies for food acquisition,
such as living inside the tubular leaf tanks of Brocchinia
species (Magnoliophyta: Bromeliaceae) (Hokche et al.
2008, Wehrtmann et al. 2016), in addition to increasing
the size of their eggs to have a more ecient direct devel-
opment, which makes the number of eggs also smaller,
thus aecting their reproductive eciency.
What makes an animal like that to live in such extreme
conditions as those of the tepuis? A catastrophic event
that separates species and creates extreme conditions may
force species to take this course. But there are more nely
tuned factors, such as interspecic competition between
organisms occupying similar niches in ecosystems, Wil-
son (1959, 1961) coined the term “taxon cycle” to refer to
variations in the distribution of species on islands. When
new species arrive, they tend to expand and the range of
distribution of resident species decreases, to a point where
they are relegated to the margin of their original distribu-
tion. If there are elevations in these spaces, it is observed
that the old species are forced to ascend in altitude and
Table 1. Altitudinal distribution of the species of freshwa-
ter crabs of the genus Microthelphusa Pretzmann, 1968.
Species Locality Altitude
(m. a.s.l.)
Species present between the Venezuelan Andes and Trinidad
M. forcarti Tabay, Merida State,
Venezuela 1,603-1,800
M. barinensis Between La Soledad
and Barinitas, Barinas
State, Venezuela 530-570
M. viloriai Santa Ana, Trujillo
State, Venezuela 1,500
M. racenisi Rancho Grande, Aragua
State, Venezuela 1,400-2,000
M. ginesi El Guacatal, Hacienda
El Limón, Distrito
Federal, Venezuela 1,224
M. turumikiri Mount Turumikire,
Sucre State, Venezuela 1,500
M. sucreensis Negro River, near the
village of Las Cabeceras.
Sucre State, Venezuela 1,730-1,980
M. odaelkae Aripo Peak, Trinidad 600-800
Species present between the Orinoco and the Amazon rivers
M. aracamuniensis Aracamuni Peak, Amazonas
State, Venezuela 1,000-1,500
M. maigualidaensis Maigualida Sierra, Amazonas
State, Venezuela 1,500
M. marahuacaensis Marahuaca Peak, Amazonas
State, Venezuela 1,500
M. guaiquinimaensis Guaiquinima Peak,
Amazonas State, Venezuela 1,380-1,400
M. meansi Potaro Siparuni,
Wokomung Massif, Guyana 1,135
M. lipkey Aracá Mountain,
Amazonas State, Brazil 1,133
M. bolivari El Dorado-Santa Elena Road,
Bolivar State, Venezuela 1,000
M. roraimaensis Mount Roraima, Bolivar
State, Venezuela 950
M. rodriguezi Rupununi River,
Melville, Guyana 827
M. wymani Brownsberg Nature Preserve
Park, Witti Creek, Surinam 506
M. furcifer Potaro-Siparuni Region,
Kuribrong River, Guyana 440
M. somanni Marauia River, affluent of
the Negro River. Near the
Venezuela Border. Brazil. 113
Suárez
48
gradually reduce their size. is allows to create a transi-
tory balance between the new and the old species, marked
by the altitudinal oors. is has been observed by Rick-
lefs (1970) and Ricklefs & Eldredge (2002) in birds of the
Antilles.
e genus Microthelphusa (Fig. 2), presents a distribu-
tion that agrees with the statements of this theory, but
also ts the model of distribution of species enunciated by
Rapoport (1975), according to which the oldest species
should be at the outer limit of the distribution of the genus.
In this analysis Microthelphusa forcarti (Pretzmann 1967) is
the one that presents the most primitive characters of its ge-
nus and is located in the Venezuelan Andes (Fig. 2, Table1),
we also know that the genus did not go past this point, so
its expansion towards the north must have coincided with
the raising of the barrier of the Venezuelan Andes and with
the gradual migration of the Orinoco towards its current
drainage. Among the species of the Andean foothills and
the Coastal Cordillera, it is worth highlighting the case of
M. ginesi Rodríguez & Esteves, 1972, found above 1,000 m
a.s.l. in the upper part of the Federal District (Venezuela)
mountains and Rodriguezus ranchograndensis (Rodríguez
1966), with a wider altitudinal range in the same moun-
tains (from 100 to 1,000 m a.s.l.) overlapping the distribu-
tion area of Microthelphusa ginesi.
To day Rodriguezus ranchograndensis is found above
1,200 m a.s.l., and M. ginesi has not been recaptured for
more than 40 years. erefore, it appears that the latter
was displaced by R. ranchograndensis and might currently
be extinct. e vertical migration of R. ranchogranden-
sis is directly associated to the urban development at the
foothills of these mountains, deforestations and pollution
streams and rivers which forced R. ranchograndensis to go
up and enter in direct competition with M. ginesi (and
generally the biggest eats the small one). A similar case is
observed in the Mount Aripo of Trinidad, where M. odae-
lkae (Bott 1970) has been substituted by Rodríguezus gar-
mani (Rathbun, 1898), possibly by the same reasons as M.
ginesi in Venezuela. is corroborates what was expressed
by Wilson (1959, 1961) in his “taxon cycle” theory.
e Microthelphusa species located between the Ori-
noco River and the northern margin of the Amazon River
(Fig. 3), present more modern characters in their distribu-
tion than in areas where there is no record of another bigger
crab genera. ey are found in low altitudinal levels. In ar-
eas where big Fredius species occur, they are found at higher
altitudes up to the top of the tepuis. Rapoport (1975), pro-
posed that the most recent species are found near the distri-
bution center of the genus, which coincides with what we
see here. But this is not an exclusive biogeographical pat-
tern of the genus Microthelphusa, the same can also be seen
within the genus Fredius. Fredius cuaoensis Suárez, 2015,
from the Upper Cuao River, at 1,000 m a.s.l., is the smallest
species in the genus. Fredius chaanjoni (Rathbun, 1905)
occurs in the mouth of this river and in its middle course.
Being the latter a species of large size, a parallel case to that
of Microthelphusa appears to occur: both species of Fredius
segregate at dierent altitudinal levels.
CONCLUSIONS
We currently accept that the extant species of freshwa-
ter crabs found on top of the tepuis are of uaternary age
and that the evolution of at least the new species of deca-
pod crustaceans, responds to the principles of the “taxon
cycle” theory. We can also state that these mountains, far
from being a lost world, are a new world where one can ap-
preciate with all intensity the force of life and the dierent
strategies of evolution that guide it. It should be noted that
several of these once pristine mountains are now under as-
sault by indiscriminate tourism that destroys the fragile
ecology of these spaces. e knowledge of these environ-
ments is still very poor, so it is not possible to determine, at
least in the case of the crustaceans, the size of the popula-
tions and their extension. All specimens known have been
found in casuistic events, which is why it is observed that
in the collections there are only two specimens of each spe-
cies.
e relatively few scientic expeditions that have been
conducted to the tepuis were mainly focused on geology
(Stern 1954, Schubert 1985, 1986, 1986a Barreat et al.
1986, Colmenares & Terán 1993, Fundación TERRA-
MAR 1993, Schneider Santos et al. 2003), botany (Gil-
liard 1942, Paba Silva & van der Hammen 1960, Molano
Campuzano 1971, Diazgranados 1979, Huber 1988, Rull
1991, Fundación TERRAMAR 1993, Estrada & Fuertes
1993, Galvis Vergara 1994, Riina 1996, Cortes & Franco
1997, Harbele 1997, Banco de Occidente 1999, Harbele
& Maslin 1999, Maslin & Burns 2000, Etter 2001, Rull
et al. 2005, 2009, Rull & Villa-Rubia 2006, Fouquet et al.
2012), reptiles, birds (Fundación TERRAMAR 1993)
and butteries (Costa et al. 2014a, 2014b, 2016, 2017,
2018, 2019a, 2019b, 2019c, 2020, [2021]a, 2021b).
Working in the mountains of the green hell, as some have
called the Amazon rainforest, is not easy. It is very expen-
sive and risky, but there is still much to discover.
ACKNOWLEDGMENTS
I thank Grisel Velázquez, Unidad de Sistemas de Infor-
mación Geográca, Centro de Ecología, IVIC (UniSIG),
for developing the model from which the distribution map
Highland crabs of the Venezuelan Guayana
49
of the species of Microthelphusa was made. I am also very
grateful to Ángel L. Viloria and Ernesto Medina, for their
critical reading of early versions of this article and to one
anonymous reviewer who made suggestions to improve
the presentation of its contents.
REFERENCES
Albert, J. S., N. R. Lovejoy & W. G. R. Crampton. 2006. Mio-
cene tectonism and the separation of cis- and trans- Andean
river basins: evidence from Neotropical shes. Journal of
South American Earth Sciences 21: 14−27.
Allibon, J., P. Monjoie, H. Lapierre, E. Jaillard, F. Bussy, D.
Bosch & F. Senebier. 2008. e contribution of the young
Cretaceous Caribbean Oceanic Plateau to the genesis of
late Cretaceous arc magmatism in the Cordillera Occiden-
tal of Ecuador. Journal of South American Earth Sciences 26:
3555−3568.
Almeida-Filho, R. & F. P. Miranda. 2007. Mega capture of the
Rio Negro and formation of the Anavilhanas Archipelago,
Central Amazonia, Brazil. Evidences in an SRTM digital el-
evation model. Remote Sensing of Evironment 110: 387−392.
Anderson, L. C., J. H. Hartman & F. Wesselingh. 2006. Close
evolutionary anities between freshwater corbulid bivalves
from the Neogene of western Amazonia and Paleogene of
the northern Great Plains, USA. Journal of South American
Earth Sciences 21: 28−48.
Andriessen, P. A. M., K. F. Helmens, H. Hooghiemstra, P. A.
Riezebos & T. van der Hammen. 1993. Absolute chronology
of the Pliocene-uaternary sediment sequence of Bogota
Area, Colombia. uaternary Science Reviews 12: 483−501.
Anger, K. 2013. Neotropical Macrobrachium (Caridea: Palae-
monidae): on the biology, origin, and radiation of freshwa-
ter-invading shrimp. Journal of Crustacean Biology 33(2):
151−183.
Barreat, F., A. Barreto, S. Gorzula, O. Huber, G. Medina-Cuervo
& C. Schubert. 1986. Reconocimiento preliminar del Maci-
zo del Chimantá, Estado Bolívar (Venezuela). Acta Cientíca
Venezolana 37: 25−42.
Bond-Buckup, G., C. G. Jara, L. Buckup, M. Pérez-Lozada, A.
A. P. Bueno, K. A. Crandall & S. Santos. 2010. New species
and new records of endemic freshwater crabs from the Atlan-
tic forest in Southern Brazil (Anomura: Aeglidae). Journal of
Crustacean Biology 30(3): 495−502.
Bott, R. 1970. Betrachtungenüber die Entwicklungs geschichte
und Verbreitung der Süsswasserkrabbennach der Sammlung
des Naturhistorischen Museums in Genf/Schweiz. Revue Su-
isse de Zoologie 77 (2): 327−344.
Brown, K. S., Jr. 1987. Biogeography and evolution of Neotropi-
cal butteries. pp. 66−104. In: Whitmore, T. C. & G. T.
Prance (eds.). Biogeography and uaternary history of Tropi-
cal America. Oxford: Clarendon Press.
Bookeld, M. E., D. P. Hemmings & P. Van Straaten. 2009.
Paleoenvironments and origin of the sedimentary phospho-
rites of the Napo Formation (Late Cretaceous, Orient Ba-
sin, Ecuador). Journal of South American Earth Sciences 28:
180−192.
Bush, M. B., P. E. de Oliveira, P. A. Colinvaux, M. C. Miller & J.
E. Moreno. 2004. Amazonian paleoecological histories: one
hill, three watersheds. Paleogeography, Paleoclimatology, Pa-
leoecology 214: 359−393.
Campos, M. R., C. Magalhães & G. Rodríguez. 2002. e fresh-
water crabs of southern Colombia and their biogeographical
anities (Brachyura: Pseudothelphusidae). Nauplius 10(1):
15−25.
Campos, M. R. & C. Magalhães. 2004. Achagua Campos, 2001,
a new synonym of Eudaniela Pretzmann, 1971, and the de-
cription of Rodriguezus gen. nov. (Decapoda: Brachyura:
Pseudothelphusidae). Nauplius 12(2): 95−97.
Candeiro, C. R. A. & T. Rich. 2010. Overview of the Late Cre-
taceous Biota of the western Sao Paulo State, Brazil. Journal
of South American Earth Sciences 29(2): 346−353.
Cardona Molina, A., U. G. Cordani & W. D. MacDonald. 2006.
Tectonic correlations of pre-Mesozoic crust from the north-
ern termination of the Colombian Andes, Caribbean region.
Journal of South American Earth Sciences 21: 337−354.
Cisne, J. L. 1974. Evolution of the world fauna of aquatic free-
living arthropods. Evolution 22(3): 337−366.
Coates, A. G., J. B. C. Jackson, L. S. Collins, . M. Cronin,
H. J. Dowsett, L. M. Bybell, P. Jung & J. A. Obando. 1992.
Closure of the Isthmus of Panama: the near-shore marine re-
cord of Costa Rica and western Panama. Geological Society of
America Bulletin 104: 814−828.
Collins, L. S., A. G. Coates, W. A. Berggren, M. P. Aubry & J.
Zhang. 1996. e Late Miocene Panama isthmian strait. Ge-
ology 24(8): 687−690.
Colmenares, O. A. & L. V. Terán. 1993. A biostratigraphy study
of Paleogene sequences in southwestern Venezuela. Palynol-
ogy 17: 67−89.
Compañía Shell de Venezuela & Creole Petroleum Corpora-
tion. 1964. Paleozoic rocks of Merida Andes, Venezuela. e
Bulletin of the American Association of Petroleum Geologists
48(1): 70−84.
Cortes, B. R. & R. P. Franco. 1997. Análisis panbiogeográ-
co de la ora de Chiribiquete, Colombia. Caldasia 19(3):
465−478.
Cortés, M., B. Colleta & J. Angelier. 2006. Structure and tecton-
ics of the central segment of the Eastern Cordillera of Colom-
bia. Journal of South American Earth Sciences 21: 437−465.
Costa, M., Á. L. Viloria, S. Attal, M. Benmesbah, S. Fratello
& Zs. Bálint. 2019b. Lepidoptera from the Pantepui. Part
VII. A distinctive Lamprospilus species from the Guiana
Highlands (Lepidoptera: Lycaenidae, eclinae). Opuscula
Zoologica (Budapest) 50(2): 111–128.
Costa, M., Á. L. Viloria, S. Attal, M. Benmesbah, A. F. E. Neild
& Zs. Bálint. 2018. Lepidoptera from the Pantepui. Part V.
New Lycaenidae (eclinae: Eumaeini). Opuscula Zoologica
(Budapest) 49(2): 163–179.
Costa, M., Á. L. Viloria, S. Attal, P. Blandin, A. F. E. Neild & M.
Benmesbah. 2020. Lepidoptera del Pantepui. Parte IX. Nue-
Suárez
50
vos Nymphalidae (Satyrinae) y Riodinidae (Riodininae). An-
tenor 7(1): 19−41.
Costa, M., Á. L. Viloria, S. Attal, A. F. E. Neild, S. Fratello &
M. Benmesbah. 2019c. Lepidoptera del Pantepui. Parte VIII.
Nuevos Nymphalidae (Charaxinae y Satyrinae) y Riodinidae
(Riodininae). Anartia 29: 20−48.
Costa, M., Á. L. Viloria, S. Attal, A. F. E. Neild, S. A. Fratello,
C. Callaghan & J. Y. Gallard. 2017. Lepidoptera del Pante-
pui. Parte IV. Nuevos Riodinidae Riodininae y Pieridae Pie-
rinae. Bulletin de la Société Entomologique de France 122(3):
269–286.
Costa, M., Á. L. Viloria, S. Attal, A. F. E. Neild, S. Fratello & S.
Nakahara. 2016. Lepidoptera del Pantepui. Parte III. Nuevos
Nymphalidae, Cyrestinae y Satyrinae. Bulletin de la Societé
Entomologique de France 121(2): 179–206.
Costa, M., Á. L. Viloria, S. Attal & A. Orellana. 2014b. Le-
pidoptera del Pantepui. Parte II. Descripción de nuevos
Nymphalidae (Papilionoidea). Bulletin de la Societé Entomo-
logique de France 119(1): 39–52.
Costa, M., Á. L. Viloria, S. Attal, A. Orellana & M. Benmesbah.
2019a. Lepidoptera del Pantepui. Parte VI. Nuevos Hespe-
riidae (Hesperiinae) y Nymphalidae (Limenitidinae y Satyri-
nae). Bulletin de la Société Entomologique de France 123(1):
77–102.
Costa, M., Á. L. Viloria, S. Attal, A. Orellana, A. F. E. Neild; M.
Benmesbah & N. V. Grishin. [2021]. Lepidoptera del Pante-
pui. Parte X. Nuevos Pieridae (Dismorphiinae) y Hesperii-
dae (Pyrrhopyginae). Antenor 7(2): 82−105.
Costa, M., Á. L. Viloria, C. Callaghan, M. Trujano-Ortega, A.
F. E. Neild, M. Benmesbah, S. Attal & N. V. Grishin. 2021.
Lepidoptera del Pantepui. Parte XI. Nuevos Riodinidae
(Riodininae), Pieridae (Dismorphiinae) y Nymphalidae (Sa-
tyrinae). Antenor (8(1): 2−28.
Costa, M., Á. L. Viloria, O. Huber; S. Attal & A. Orellana.
2014a. Lepidoptera del Pantepui. Parte I: Endemismo y ca-
racterización biogeográca. Entomotrópica 28(3): 193–216.
Cozzuol, M. A. 2006. e Acre vertebrate fauna: age, diversity,
and geography. Journal of South American Earth Sciences 21:
185−203.
Cracra, J. 1988. Deep-history biogeography: retrieving the his-
torical pattern of evolving continental biotas. Systematic Zool-
ogy 37(3): 221−236.
Cumberlidge, N. 2007. A new species of freshwater crab of
the genus Microthelphusa (Brachyura: Pseudothelphusidae)
from a remote isolated cloud forest on a tabletop mountain
in western Guyana, South America. Zootaxa 1447: 57−62.
Cumberlidge, N., P. K. L. Ng, D. C. J. Yeo, C. Magalhães, M. R.
Campos, F. Alvarez, T. Naruse, S. R. Daniels, L. J. Esser, F. Y.
K. Attipoe, F. L. Clotilde-Ba, W. Darwall, A. McIvor, J. E. M.
Baillie, B. Collen & M. Ram. 2009. Freshwater crabs and the
biodiversity crisis: importance, threats, status and conserva-
tion challenges. Biological Conservation 142: 1665−1673.
Cumberlidge, N., F. Alvarez & J. L. Villalobos. 2014. Results of
the global conservation assessment of the freshwater crabs
(Brachyura, Pseudothelphusidae and Trichodactylidae): the
Neotropical Region, with and update on diversity. Zookeys
457: 133−157.
Cunha Ribeiro, A. 2006. Tectonic history and biogeography of
the freshwater shes from the coastal drainages of eastern Bra-
zil: an example of faunal evolution associated with a divergent
continental margin. Neotropical Ichthyology 4(2): 225−246.
Dentzien-Dias, P. C., C. L. Schultz & C. Bertoni-Machado.
2008. Taphonomy and palaecology inferences of vertebrate
ichnofossils from Guará Formation (Upper Jurassic), south-
ern Brazil. Journal of South American Earth Sciences 25:
196−202.
Diaz, H. & G. Rodríguez. 1977. e branchial chamber in ter-
restrial crabs: a comparative study. Biological Bulletin 153:
485−504.
Diazgranados, D. 1979. Geografía. pp. 7−77. In: La Amazonia
colombiana y sus recursos. Proyecto Radargramétrico del Ama-
zonas. Colombia. Bogotá, D. C.: Italgraf, S. A.
Estrada, J. & J. Fuertes. 1993. Estudios botánicos de la Guayana
Colombiana, IV. Notas sobre la vegetación y ora de la Sierra
de Chiribiquete. Revista de la Academia Colombiana de Cien-
cias Exactas, Físicas y Naturales 18(71): 488−498.
Etter, A. (ed.). 2001. Puinawai y Nukak. Caracterización eco-
lógica de dos reservas Nacionales, Naturales de la Amazonia
colombiana. Ambiente y desarrollo. Serie Investigación 2. Bo-
gotá: Instituto de Estudios Ambientales para el Desarrollo,
Universidad Javeriana, 271 pp.
Fabbrin Pires, E. & M. Guerra Sommer. 2009. Plant-arthropod
interaction in the Early Cretaceous (Berriasian) of the Ara-
ripe Basin, Brazil. Journal of South American Earth Sciences
27: 50−59
Feijó Ramos, M. I. 2006. Ostracods from the Neogene Solimoes
Formation (Amazonas, Brazil). Journal of South American
Earth Sciences 21: 87−95.
Feldmann, R. M. 2003. e Decapoda: new initiatives and
novel approaches. Journal of Paleontology 77(6): 1021−1039.
Feldmann, R. M. & C. E. Schweitzer. 2006. Paleobiogeography
of Southern Hemisphere decapod Crustacea. Journal of Pale-
ontology 80(1): 83−103.
Fouquet, A., B. P. Noonan, M. T. Rodrigues, N. Pech, A. Gilles
& N. J. Gemmell. 2012. Multiple uaternary refugia in East-
ern Guiana Shield revealed by comparative phylogeography
of 12 frog species. Systematic Biology 61(3): 461−489.
Fundación TERRAMAR (ed.). 1993. Informe técnico sobre los
Tepuyes. Formación Roraima, Venezuela. Acta Terramaris 6:
1−74.
Flynn, J. J., R. Charrier González, D. A. Cro, P. B. Gans, T. M.
Herriott, J. A. Wertheim & A. R. Wyss. 2008. Chronologic
implications of new Miocene mammals from Cura-Mallin
and Trapa Trapa Formations, Laguna de Laja area, south
central Chile. Journal of South American Earth Sciences 26:
412−423.
Galvis Vergara, J. 1994. Estudio geológico de la Sierra de Chiri-
biquete y zonas aledañas (Parque Nacional Natural Chiribi-
quete). Revista de la Academia Colombiana de Ciencias Exac-
tas, Físicas y Naturales 19(73): 275−286.
Highland crabs of the Venezuelan Guayana
51
Gayet, M., J. C. Rage, . Sempere & P. Y. Gagnier. 1992. Moda-
lités des échanges de vertébrés continentaux entre lAmérique
du Nord et lAmérique du Sud au Crétacee Superieur et au
Paléocène. Bulletin de la Societe Géologique de France 163(6):
781−791.
Gilliard, E. T. 1942. e Cordillera Macarena, Colombia. e
Geographical Review 32(3): 463−470.
Habib, D. & J. A. Miller. 1989. Dinoagellate species and or-
ganic facies evidence of marine transgression and regression
in the Atlantic Coastal Plain. Palaeogeography, Palaeoclima-
tology, Palaeoecology 74: 23−47.
Hamilton, H., S. Caballero, A. G. Collins & L. R. Brownell, Jr.
2001. Evolution of river dolphins. Proceedings of the Royal
Society B 268: 549−556.
Haq, B. U., J. Hardenbo & P. R. Vail. 1987. Chronology of uc-
tuating sea levels since Triassic. Science 235: 1156−1167.
Harberle, S. 1997. Upper uaternary vegetation and climate
history of the Amazon Basin: correlating marine and ter-
restrial pollen records. Proceedings of the Ocean Drilling Pro-
gram, Scientic Results 155: 381−396.
Harberle, S. G. & M. A. Maslin. 1999. Late uaternary veg-
etation and climate change in the Amazon Basin based on a
50.000 year pollen record from the Amazon Fan, ODP Site
932. uaternary Research 51: 27−38.
Harrington, H. J. 1962. Paleogeographic development of South
America. Bulletin of the American Association of Petroleum
Geologists 46(10): 1773−1814.
Haug, G. H. & R. Tiedemann. 1998. Eect of formation of the
Isthmus of Panama on Atlantic Ocean thermohaline circula-
tion. Nature 393: 673−676.
Haug, G. H., R. Tiedemann, R. Zahn & A. Ch. Ravelo. 2001.
Role of Panama upli on oceanic freshwater balance. Geology
29(3): 207−210.
Haug, J. T., J. W. Martin & C. Haug. 2015. A 150 million year old
crab larva and its implications for the early rise of brachyuran
crabs. Nature Communications doi: 10.1038/ncomms7417.
Hokche, O., P. E. Berry & O. Huber. 2008. Nuevo catálogo de
la ora vascular de Venezuela. Caracas: Fundación Instituto
Botánico de Venezuela Dr. Tobías Lasser, 859 pp.
Hoogmoed, M. S. 1979. e herpetofauna of the Guianan re-
gion. pp. 241-279. In: Duellman, W. E. (ed.). e South
American herpetofauna: its origin, evolution and dispersal.
Monograph 7. Lawrence: University of Kansas, Museum of
Natural History.
Hoorn, C. 1993. Marine incursions and inuence of Andean
tectonics on the Miocene depositional history of northwest-
ern Amazonia: results of a palynostratigraphic study. Palaeo-
geography, Palaeoclimatology, Palaeoecology 105: 267−309.
Hoorn, C. 1994. An environmental reconstruction of the pa-
laeo-Amazon River system (Middle-Late Miocene, NW
Amazonia). Palaeogeography, Palaeoclimatology, Palaeoecol-
ogy 112: 187−238.
Hoorn, C., J. Guerrero, A. G. Sarmiento & M. A. Lorente. 1995.
Andean tectonics as a cause for changing drainage patterns in
Miocene northern South America. Geology 23(3): 237−240.
Hoorn, C. & H. Vonhof. 2006. Neogene Amazonia: Introduc-
tion to the special issue. Journal of South American Earth Sci-
ences 21(1-2): 1−4.
Hoorn, C. & F. P. Wesselingh (eds.). 2010. Amazonia: landscape
and species evolution. A look into the past. Chichester, UK and
Hoboken, NJ, USA: Wiley-Blackwell, xiii + 447 pp.
Huber, O. 1987. Consideraciones sobre el concepto de Pante-
pui. Pantepui (Caracas) 1(2): 2−10.
Huber, O. 1988. Vegetación y ora del Pantepui, Región Guaya-
na. Acta Botánica Brasileira 1(2): 41−52.
Hulka, C., K. U. Gräfe, B. Sames, C. E. Uba & C. Heubeck.
2006. Depositional setting of the Middle Miocene Yecua
Formation the Chaco Foreland Basin, southern Bolivia. Jour-
nal of South American Earth Sciences 21: 135−150.
Iturralde-Vinent, M. A. 2003. e conicting paleontologic
versus stratigraphic record of the formation of the Caribbean
Seaway. pp. 75-88. In: Bartolini, C., R. T. Buer & J. Blick-
wede (eds.). e Circum-Gulf of Mexico and the Caribbean:
Hydrocarbon habitats, basin formation, and plate tectonics:
AAPG Memoir 79.
Jaimes, E. & M. de Freitas. 2006. An Albian-Cenomanian uncon-
formity in the northern Andes: evidence and tectonic signi-
cance. Journal of South American Earth Sciences 21: 466−492.
Jasper, A., D. Uhl & V. Guerra-Sommer & M. Mosbrugger.
2008. Palaeobotanical evidence of wildres in the Late Pa-
leozoic of South America – early Permian, Rio Bonito For-
mation, Paraná Basin, Rio Grande do Sul, Brazil. Journal of
South American Earth Sciences 26: 435−444.
Kaandorp, R. J. G., F. P. Wesselingh, & H. B. Vonhof. 2006. Eco-
logical implications from geochemical records of Miocene
Western Amazonian bivalves. Journal of South American
Earth Sciences 21: 54−74.
Kay, R. F. & M. A. Cozzuol. 2006. New platyrrhine monkeys
from the Solimoes Formation (Late Miocene, Acre State,
Brazil). Journal of Human Evolution 50: 673−686.
Klaus, S., C. Magalhaes, R. Salas-Gismondi, M. Gross & P. O.
Atoine 2017. Palaeogene and Neogene brachyurans of the
Amazon Basin: a revisited rst appearance date for primary
freshwater crabs (Brachyura, Trichodactylidae). Crustaceana
90(7-10): 953−967.
Kroonenberg, S. B., J. G. M. Bakker & A. M. van der Wiel. 1990.
Late Cenozoic upli and paleogeography of the Colombian
Andes: constraints on the development of high-Andean bio-
ta. Geologie en Mijnbouw 69: 279−290.
Lasso, C. A., J. Hernández-Acevedo, E. Alexander, J. C. Señaris,
L. Mesa, H. Samudio, J. Mora-Day, C. Magalhaes, A. Shushu,
E. Mauruwanaru & R. Shoni. 2013. Aquatic biota: shes,
decapod crustaceans and mollusks of the Upper Essequibo
Basin (Konashen COCA), southern Guyana. pp. 43−54.
In: McCullough, J., P. Hoke, P. Naskrecki & Y. Osei-Owusu
(eds.). A rapid Biological assessment of the Konashen Com-
munity Owned Conservation Area. Arlington, VA & George-
town, Guyana: Conservation International.
Latrubesse, E. M., S. A. F. da Silva, M. Cozzuol & M. L. Absy.
2007. Late Miocene continental sedimentation in south-
Suárez
52
western Amazonia and its regional signicance: biotic and
geological evidence. Journal of South American Earth Sciences
23: 61−80.
Leier, A., N. Mcuarrie, C. Garcione & J. Eiler. 2013. Stable
isotope evidence for multiple pulses of rapid surface upli in
the Central Andes, Bolivia. Earth and Planetary Science Let-
ters 371/372: 49−58.
Leonhardt, A. & M. L. Lorscheitter. 2010. e last 25,000 years
in the eastern Plateau of Southern Brazil according to Alpes
de Sao Francisco record. Journal of South American Earth
Sciences 29: 454−463.
Limarino, C. O. & L. A. Spalletti. 2006. Paleogeography of the
upper Paleozoic basins of southern South America: an over-
view. Journal of South American Earth Sciences 22: 134−155.
Lovejoy, N. R., J. S. Albert & W. G. R. Crampton. 2006. Mio-
cene marine incursions and marine/freshwater transitions:
evidence from Neotropical shes. Journal of South American
Earth Sciences 21: 5−13.
Lovejoy, . E. 2017. e Amazon region. Science Advances.
3(11): eaar3677.
Lundberg, J. G. 1992. A Miocene fossil of the Amazonian sh
Arapaima (Teleostei, Arapaimidae) from the Magdalena
River region of Colombia – biogeography and evolutionary
implications. Biotropica 24(1-2):14.
Magalhães, C. & G. Pereira. 2007. Assessment of the Crustacea
Decapoda diversity in the Guayana Shield region aiming
conservation decisions. Biota Neotropica 7(2): 111−124.
Magalhaes, C. 2010. A new species of freshwater crabs of the ge-
nus Microthelphusa from a Tepui in the Serra do Araca, state
of Amazonas, Brazil. pp. 453−460. In: Franzen, C., S. de
Grave & P. Ng (eds.). Studies on Malacostraca. Lipke Bijdeley
Holthuis Memorial Volume. Monographs 14.
Maguire, B. 1979. Guyana, region of the Roraima Sandstone
Formation. pp. 223−238. In: K. Larsen & L. B. Holm-
Nielsen (eds.). Tropical Botany. London, New York, San
Francisco: Academic Press.
Malabarba, L. R., R. E. Reis, R. P. Vari, Z. M. S. Lucena & C.
A. S. Lucena 1998. Phylogeny and classication of Neotropical
shes. Porto Alegre, Brasil: EDIPUCRS, 603 pp.
Mantelatto, F. L., L. Pileggi, H. Suárez & C. Magalhães. 2008.
First record and extension of the known distribution of the
inland prawn, Macrobrachium aracamuni Rodríguez, 1982
(Decapoda, Palaemonidae) in Brazil. Crustaceana 81(2):
241−246.
Martínez, J. I., Y. Yokoyama, A. Gómez, A. Delgado, H. Mat-
suzaki & E. Rendón. 2010. Late Holocene marine terraces
of the Cartagena region, Southern Caribbean: the product
of neotectonism or former high stand in sea level? Journal of
South American Earth Sciences 29: 214-224.
Maslin, M. A. & S. J. Burns. 2000. Reconstruction of the Ama-
zon Basin eective moisture availability over the past 14,000
years. Science 290: 2285−2287.
Meschede, M. & W. Frisch. 1998. A plate tectonic model for the
Mesozoic and Early Cenozoic history of the Caribbean Plate.
Tectonophysics 296: 269−291.
Molano Campuzano, J. 1971. Un tesoro del Mundo: la Sierra
de la Macarena. Boletín de la Sociedad Geográca Colombiana
27(103): 1−31.
Monsch, K. A. 1998. Miocene sh faunas from the northwest-
ern Amazonian basin (Colombia, Peru, Brazil). With evi-
dence of marine incursions. Palaeogegraphy, Palaeoclimatol-
ogy, Palaeoecology 143: 31−50.
Müller, P. 1973. e dispersal centers of terrestrial vertebrates in the
Neotropical realm: a study in the evolution of the Neotropical bio-
ta and its native landscape. e Hague: Junk, 244 pp.
Muñoz-Torres, F. A., R. C. Whatley & D. van Harten. 2006.
Miocene ostracod (Crustacea) biostratigraphy of the upper
Amazon Basin and evolution of the genus Cyprideis. Journal of
South American Earth Sciences 21: 75−86.
Murdock, T. Q., A. J. Weaver & A. F. Fanning. 1997. Palaeocli-
matic response of the closing of the Isthmus of Panama in a
coupled ocean-atmosphere model. Geophysical Research Let-
ters 24(3): 253−256.
Neild, A. F. E. 1996. e butteries of Venezuela. Part I. Nym-
phalidae I (Limenitidinae, Apaturinae, Charaxinae). A com-
prehensive guide to the identication of adult Nymphalidae,
Papilionidae, and Pieridae. Greenwich, London: Meridian
Publications, 144 pp.
Neild, A. F. E. 2008. e butteries of Venezuela. Part 2.
Nymphalidae II (Acraeinae, Libytheinae, Nymphalinae,
Ithomiinae, Morphinae). A comprehensive guide to the iden-
tication of adult Nymphalidae, Papilionidae, and Pieridae.
Greenwich, London: Meridian Publications, 275 pp.
Ortmann, A. E. 1902. e geographical distribution of fresh-
water decapods and its bearing upon ancient geography.
Proceedings of the American Philosophical Society 41(171):
267−400.
Paba Silva, F. & T. van der Hammen. 1960. Sobre la Geología
de la Parte Sur de la Macarena. Bogotá: Servicio Geológico
Nacional, 30 pp.
Pedraza M. & M. Tavares. 2014. A new species of freshwater
crabs of the genus Microthelphusa Prezmann, 1968 (Crusta-
cea: Brachyura: Pseudothelphusidae) from the Amazon re-
gion of Guyana. Zootaxa 3847(2): 267−274.
Pereira, G., C. A. Lasso, J. Mora-Day, C. Magalhaes, M. A. Mo-
rales-Betancourt & M. Campos. 2009. Lista de los crustáceos
decápodos de la cuenca del Río Orinoco (Colombia-Vene-
zuela). Biota Colombiana 10(1-2): 75−87.
Perkins, S. 2014. Why the Amazon ows backward. Science News.
https://www.science.org/content/article/why-amazon-ows-
backward
Posada-Swaord, A. 2017. Advances. Amazon Atlantis. Scienti-
c American 317(1):12-14.
Pretzmann, G. 1967. Über einige südamerikanische Süsswasser-
krabben (Pseudothelphusidae). Vorläuge Mitteilung. Ento-
mologische Nachrichtenblatt 14: 23−26.
Pretzmann, G. 1968. Weitere neue südamerikanische Süsswas-
serkrabben. Entomologische Nachrichtenblatt 15(2): 1−6.
Ramon, J. C. & A. Rosero. 2006. Multiphase structural evolu-
tion of the western margin of the Girardot subbasin, Upper
Highland crabs of the Venezuelan Guayana
53
Magdalena Valley, Colombia. Journal of South American
Earth Sciences 21: 493−509.
Ramos, V. A. & M. Moreno. 2006. Tectonic evolution of the
Colombian Andes. Journal of South American Earth Science
21: 319−321.
Rapoport, E. H. 1975. Areografìa. Estrategias geográcas de las
especies. México: Fondo de Cultura Económica, 214 pp.
Räsänen, M. E, A.M. Linna, J. C. R. Santos & F. R. Negri. 1995.
Late Miocene tidal deposition in the Amazonian foreland
basin. Science 269: 386−390.
Rathbun, M. 1898. A contribution to a knowledge of the fresh-
water crabs of America. e Pseudothelphusinae. Proceedings
of the U.S. National Museum 21 (1158): 507−537.
Rathbun, M. 1905. Les crabs d ‘eau douce (Potamonidae). Nou-
velles Archives du Museum National d’ Histoire Naturelle
4(8): 33−122.
Rebata, H. L. A., M. E. Räsänen, M. K. Gingras, V. Vieira, Jr.,
M. Barberi & G. Irion. 2006. Sedimentology and ichnol-
ogy of tide-inuenced Late Miocene successions in western
Amazonia: the gradational transition between the Pebas and
Nauta formations. Journal of South American Earth Sciences
21: 96−119.
Restrepo, J. D. & A. López. 2008. Morphodynamics of the Pa-
cic and Caribbean deltas of Colombia, -South America.
Journal of South American Earth Science 25: 1−21.
Riccardi, A. C. 1987. Cretaceous paleogeography of southern
South America. Paleogeography, Palaeoclimatology, Palaeo-
ecology 59: 169−195.
Riina, R. 1996. El elemento togeográco andino en la Provincia
Pantepui, región Guayana, Venezuela. Caracas: Universidad
Central de Venezuela. Facultad de Ciencias. Escuela de Bi-
ología, 107 pp. [biology thesis]
Ricklefs, R. E. 1970. Stage of taxon cycle and distribution of
birds on Jamaica, Greater Antilles. Evolution 24: 475–477.
Ricklefs, R. E. & B. Eldredge. 2002. e concept of the Taxon
Cycle in biogeography. Global Ecology and Biogeography 11:
353−361.
Rodríguez, G. 1966. e freshwater crabs of the genus Pseudo-
thelphusa from northern Venezuela and Trinidad. Zoologische
Mededelingen 41:111−135, 7 pls.
Rodríguez, G. & H. Díaz. 1977. Note sur queques restes de
Crabes d`eau douce (Pseudothelphusidae) provenant d`un
Kjoekken-Moedding du Venezuela. Crustaceana 33(1):
107−109.
Rodríguez, G. 1980. Description préliminaire de quelques es-
pèces et genres nouveaux de Crabes deau douce de lAme-
rique tropicale. Bulletin du Museum National dHistoire
Naturelle 4(2): 889−894.
Rodríguez, G. 1982. Les crabes deau douce dAmérique. Famille
des Pseudothelphusidae. FauneTropicalle XXII. Paris: ORS-
TOM Editions, 223 pp.
Rodríguez, G. 1992. e eshwater crabs of America. Family
Trichodactylidae and supplement to the family Pseudothelphusi-
dae. Faune Tropicale XXXI. Paris: Orstom Editions. 189 pp.
Rodríguez G. 1997. Trichodactylid crabs. pp. 80−83. In: Kay, R.
F., R. H. Madden, R. L. Cifelli & J. J. Flynn (eds.). Vertebrate
paleontology in the Neotropics. e Miocene fauna of La Venta,
Colombia. Washington, D. C.: Smithsonian Institution.
Rodríguez, G. & M. R. Campos. 2000. Microthelphusa sucreen-
sis, a new species of Pseudothelphusidae (Decapoda), with
notes on abnormalities in the sexual appendages of freshwa-
ter crabs. Journal of Crustacean Biology 20 (special number
2): 332−336.
Rodríguez, G. & A. E. Esteves. 1972. Una nueva especie de can-
grejo de agua dulce (Decapoda: Pseudothelphusidae) del
centro de Venezuela. Memoria de la Sociedad de Ciencias Na-
turales La Salle 92: 133−137.
Rossetti, D. F., P. Mann de Toledo & A. M. Góes. 2005. New
geological framework for Western Amazonia (Brazil) and
implications for biogeography and evolution. uaternary
Research 23: 78−89.
Ruban, D. A., H. Zerfass & V. I. Pugatchev. 2009. Triassic syn-
thesis of southern South America (Sothwestern Gondwana)
and the western Caucasus (the northern Neothethys), and
global tracing of their boundaries. Journal of South American
Earth Sciences 28: 155−167.
Rull, V. 1991. Contribución a la paleoecología de Pantepui y la
Gran Sabana (Guayana Venezolana): clima, biogeografía y
ecología. Scientia Guaianae 2: 133 pp.
Rull, V. 1999. Paleoclimatology and sea-level history in Venezu-
ela. Interciencia 24(2): 92−101.
Rull, V., T. Vegas-Villarrúbia & S. Nogué. 2005. Cambio climá-
tico y diversidad de la ora vascular en las montañas tabulares
de Guayana. Orsis 20: 61−71.
Rull, V. & T. Vegas-Villarrúbia. 2006. Unexpected biodiversity
loss under global warming in the Neotropical Guayana high-
land: a preliminary appraisal. Global Change Biology 12: 1−9.
Rull, V. & T. Vegas-Villarrúbia, S. Nogué & O. Huber. 2009.
Conservation of the unique Neotropical vascular ora of the
Guayana highlands in the face of global warming. Conserva-
tion Biology 23(3): 1323−1327.
Shell de Venezuela & Creole Petroleum Corporation. 1964.
Paleozoic rocks of Mérida Andes, Venezuela. e Bulletin of
the American Petroleum Association of Petroleum Geologists
48(1): 70−84.
Schneider Santos, J. O., P. E. Potter, N. J. Reis, L. A. Hartmann,
I. R. Fletcher & N. J. McNaughton. 2003. Age, source and
regional stratigraphy of the Roraima Super group and Ror-
aima-like outliers in northern South America base on U-Pb
geochronology. Geological Society of America Bulletin 115(3):
331−348.
Schram, F. R. 2001. Phylogeny of decapods: moving towards a
consensus. Hydrobiologia 449: 1−20.
Schubert, C. 1985. Orígenes de la Gran Sabana (Escudo de
Guayana), Venezuela. Nachrichten der Deustsch-Venezolani-
schen Gesellscha. Jg. III. 3/4: 164−168.
Schubert, C. & P. Fritz. 1985. Radiocarbon ages of peat, Guayana
Highlands (Venezuela). Naturwissenschaen 72: 427−429.
Suárez
54
Schubert, C. 1986. Paleoenvironmental studies in the Guayana
Region Southeast Venezuela. Current Research in the Pleisto-
cene 3: 88−90.
Schubert, C. 1986a. Terrazas aluviales en el escudo de Guayana:
Informe preliminar. Acta Cientíca Venezolana 37: 226−238.
Shubert, C. 1993. El mundo perdido no está en el Macizo de
Guayana. Revista Geográca Venezolana 34: 129−134.
Schubert, C., P. Fritz & R. Aravena. 1994. Late uaternary pa-
leoenvironmental studies in the Gran Sabana (Venezuelan
Guayana Shield). uaternary International 21: 81−90.
Shephard, G. E, R. D. Muller, L. Liu & M. Gurnis. 2010. Mio-
cene drainage reversal of the Amazon River driven by plate-
mantle interaction. Nature Geoscience Letters 3: 870−875.
Silva Tamayo, J. C., G. M. Sierra & L. G. Correa. 2008. Tec-
tonic and climatic driven uctuations in the stratigraphic
base level of a Cenozoic continental coal basin, northwest-
ern Andes. Journal of South American Earth Sciences 26:
369−382.
Souza-Carvalho, E. A., C. Magalhaes & F. L. Mantelatto. 2017.
Molecular phylogeny of the Trichodactylus uviatilis La-
treille, 1828 (Brachyura: Trichodactylidae) species complex.
Journal of Crustacean Biology 37(2): 187−194.
Stephan, J. F., B. Mercier de Lepinay, E. Calais, M. Tardy, C.
Beck, J. C. Carfatan, J. L. Olivet, J. M. Vila, P. Bouysse, A.
Mauret, J. Bourgois, J. M. ery, J. Tournon, R. Blanchet &
J. Dercourt. 1990. Paleogeodynamic maps of the Caribbean:
14 steps from Lias to Present. Bulletin de la Société Géologique
de France 8(6): 915−919.
Stern, C. M. 1954. La génesis del Casiquiare. Acta Cientíca
Venezolana 5(2): 52−53.
Stevcic, Z. 1971. e main features of brachyuran evolution.
Systematic Zoology 20: 331−340.
Steyermark, J. A. 1979. Plant refuge and dispersal centres in
Venezuela: their relict and endemic elements. pp. 185−221.
In: Larsen, K. & L. B. Holm-Nielsen (eds.). Tropical Botany.
London, New York, San Francisco: Academic Press.
Suárez, H. 2006. New species of freshwater crab from Venezuela
and redescription of Microthelphusa rodriguezi Pretzmann,
1968 (Brachyura: Pseudothelphusoidea: Pseudothelphusi-
dae). Journal of Crustacean Biology 26(2): 242−247.
Suárez, H. 2015. Six new species of freshwater crabs from Pan-
tepui, Venezuela (Crustacea: Decapoda: Pseudothelphusi-
dae). Anartia 25: 64−94.
Teixeira, W., M. A. Hamilton, V. A. V. Girardi, F. M. Faleiros &
R.E. Ernst. 2019. U-Pb baddeleyite ages of key dyke swarms
in the Amazonian Craton (Carajás/Río María and Río Apa
areas): tectonic implications for events at 1880, 1110 Ma,
535 Ma and 200 Ma. Precambrian Research 329: 138–155.
Vega, F. J. & R. Feldmann. 1991. Fossil crabs (Crustacea, De-
capoda) from the Maastrichtian Difunta Group, Northeast-
ern Mexico. Annals of the Carnegie Museum 60(2): 163−177.
Von Sternberg, R., N. Cumberlidge & G. Rodríguez. 1997. On
the marine sister groups of the freshwater crabs (Crustacea:
Decapoda: Brachyura). Journal of Zoological Systematics and
Evolutionary Research 37: 19−38.
Wade, L. 2013. e Amazon in 4D. Science 341: 234−235.
Wade, L. 2017. Was the Amazon once an ocean? Science. doi:
10.1126/science.aal1142.
Walter, H. 1976. Die oekologischen Systeme der Kontinente (Bio-
geosphaere). I. Stuttgart: G. Fischer Stuttgart, 131 pp.
Webb, S. D. 1995. Biological implications of the Middle Mio-
cene Amazon Seaway. Science Perspectives 269: 361−362.
Weeks, L. G. 1956. Paleogeografía de América de Sur. Lima: Uni-
versidad Mayor de San Marcos, Facultad de Letras, Instituto
de Geografía, 76 pp.
Magalhaes, C. & O. C. Bello-González. 2016. First conrmed
report of a primary freshwater crab (Brachyura: Pseudothel-
phusidae) associated with bromeliads in the Neotropics.
Journal of Crustacean Biology 36(3): 303−309.
Wesselingh, F. P. & O. Macsotay. 2006. Pachydonhettneri (An-
derson, 1928) as indicator for Caribbean-Amazonian low-
land connections during the Early- Middle Miocene. Journal
of South American Earth Sciences 21: 49−53.
Westaway, R. 2006. Late Cenozoic sedimentary sequences in
Acre state, southwestern Amazonia: uvial or tidal? Deduc-
tions from the IGCP 449 eldtrip. Journal of South Ameri-
can Earth Sciences 21: 120−134.
Wilson, E. O. 1959. Adaptive shi and dispersal in a tropical ant
fauna. Evolution 13: 122–144.
Wilson, E. O. 1961.e nature of the taxon cycle in the Melane-
sian ant fauna. American Naturalist 95: 169–193.
Wilson, E. O. 1992.e Diversity of Life. Cambridge: Belknap,
464 pp.
Woodburne, M. O. 2010. e Great American Biotic Inter-
change: dispersals, tectonics, climate, sea level and holding
pens. Journal of Mammal Evolution 17(4): 245–264.
