Maccaffertium annae sp. n. is described in the Mexican amber of early Miocene age. It constitutes the first species of mayfly (Ephemeroptera), the first record of the family Heptageniidae to be described from this amber, and also the first fossil record of the genus Maccaffertium. The species is represented by male and female imagos in one piece of amber

Macadam, C R

Ross, Andrew

National Museums Scotland Research Repository

 
 
 
 
 
 
 
 
Macadam, C. R & Ross, A. J. 2016. A New Species of Mayfly, Maccaffertium annae sp. n. 
(Ephemeroptera: Heptageniidae) from Mexican Amber (Miocene). Boletín de la Sociedad 
Geológica Mexicana, 68 (1): 1-5. (2016) 
ISSN: 1405-3322 
http://dx.doi.org/10.1093/molbev/msw036 
 
 
 
http://repository.nms.ac.uk/1638 
 
Deposited on: 22 July 2016 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
NMS Repository – Research publications by staff of the National Museums Scotland 
 
http://repository.nms.ac.uk/  
Maccaffertium annae sp. nov. (Ephemeroptera: Heptageniidae) from Mexican Amber (Miocene) 1
Abstract
Maccaffertium annae sp. n. is described in the Mexican amber of early Miocene age. It constitutes the first species of mayfly 
(Ephemeroptera), the first record of the family Heptageniidae to be described from this amber, and also the first fossil record of the 
genus Maccaffertium. The species is represented by male and female imagos in one piece of amber.
Keywords: Amber, Ephemeroptera, Maccaffertium, Miocene, Mexico.
Resumen
Maccaffertium annae sp. n. se describe en el ámbar mexicano del Mioceno temprano. Constituye la primera especie de efímera 
(Ephemeroptera), el primer registro de la familia Heptageniidae que se ha descrito de este ámbar, y el primer registro fósil del género 
Maccaffertium. La especie está representada por imagos masculinos y femeninos en una pieza de ámbar.
Palabras clave: Ámbar, Ephemeroptera, Maccaffertium, Mioceno, México.
Boletín de la Sociedad Geológica Mexicana
Volumen 68, núm. 1, 2016, p. 1-5
A New Species of Mayfly, Maccaffertium annae sp. nov. (Ephemeroptera: 
Heptageniidae) from Mexican Amber (Miocene)
Craig R. Macadam1,*, Andrew J. Ross2
1 Buglife – The Invertebrate Conservation Trust, Balallan House, 24 Allan Park, Stirling, FK8 2QG, Scotland, UK.
2 National Museum of Scotland, Chambers Street, Edinburgh, EH1 1JF, Scotland, UK.
* craig.macadam@buglife.org.uk
1. Introduction
Mexican amber is one of the major types of fossiliferous 
ambers in the world and has yielded about 200 families of 
arthropods so far. Most of the amber has been extracted 
from Simojovel in Chiapas State. The resin was produced 
by the legume tree Hymenaea mexicana which grew in a 
forest close to a mangrove swamp (Solórzano-Kraemer, 
2010). The amber is considered to be about 15 – 20 million 
years old which corresponds to the Burdigalian stage of the 
Miocene (International Chronostratigraphic Chart v2014/02 
www.stratigraphy.org).
Mayflies (Ephemeroptera) are well known from the 
fossil record with more than 200 species having been 
described. However, they are comparatively rare in amber 
with 46 species described in amber from: the Baltic (31 
species); New Jersey (5); Dominican Republic (4); Burma 
(3); Russia (2); and China (1). Their rarity is not surprising 
given that they spend most of their life cycle as nymphs in 
streams or other freshwater habitats. The adults (imagos) 
live from a few hours to a few days. Imago mayflies have 
no attraction to resin, though may use trees as somewhere 
to rest. For them to get trapped in sticky resin is purely by 
accident.
Three families of mayflies have been recorded from 
Mexican amber so far (Baetidae, Leptohyphidae and 
Leptophlebiidae in Solórzano-Kraemer, 2010) however no 
species has hitherto been described and named.  The species 
described here constitutes the first species of mayfly to be 
named and the first record of the family Heptageniidae in 
Mexican amber. The new species is based on a male and a 
female imago in the same piece of amber (Figure 1)
Macadam and Ross2
2. Systematic Paleontology
Order: Ephemeroptera Hyatt & Arms, 1890
Family: Heptageniidae Needham, 1901
Genus: Maccaffertium Bednarik, 1979
Type species. Maccaffertium mexicanum Ulmer, 1920
Maccaffertium annae sp. n.
Holotype. NMS G.2008.34.3.1 (Figures 1-3) imago 
male in a piece of Mexican amber, nearly complete though 
missing half of the left fore-wing, most of the length of the 
caudal filaments (cerci) and tips of left fore-leg, mid-leg, and 
both hind-legs. The right fore-leg is detached. Some parts 
such as the eyes, thorax and abdomen shrunken. Housed 
in the National Museums Collection Centre, National 
Museums Scotland, Edinburgh, purchased from Roland 
Torikian.
Paratype. NMS G.2008.34.3.2 (Figure 1) imago female 
in the same piece of amber as the holotype, complete imago 
just missing the tips of its left fore- and mid-legs, and entire 
left hind-leg. The similarity of fore-wing venation and that 
the imagos were trapped at the same time (during swarming) 
indicate that this specimen is conspecific with the holotype.
Type locality. Simojovel, Chiapas State, Mexico.
Type age. Burdigalian (Miocene).
Etymology. The specific epithet is named after Ann 
Ross, daughter of AJR.
Diagnosis. This species belongs to the Heptageniidae 
based on the presence of two pairs of intercalary veins in 
the cubital field of the fore-wing - the shorter pair adjacent 
to Cu1, and five tarsal segments in the fore-leg. This species 
was placed in the genus Maccaffertium based on its fore-
wing venation and the morphology of the penes, the latter 
bearing a superficial resemblance to those of the type species 
M. mexicanum Ulmer. It differs from other species in this 
genus by the following combination of characters: fore-wing 
cross-veins reduced, pigmented in the Radial and Medial 
fields; arranged in four transverse bands; penis lobes sub-
quadrate, divergent, split to base.
Description. Male imago. Measurements: Length from 
tip of head to tip of abdomen (excl. genitalia) – 5.3 mm; 
fore-wing length – 5.8 mm; fore-wing width – 2.0 mm; 
hind-wing length – 2.0 mm; hind-wing width – 1.1 mm.
Abdomen 3.1 mm long; 10th abdominal segment with 
two pairs of small projections at the posterior corners near 
bases of caudal filaments and forceps.  
Head with compound eyes large and separated by 0.3 
mm dorsally, antennae longer than the head.
Fore-wing hyaline (Figure 2), venation (nomenclature 
based on Elliott and Humpesch, 1983) typical of 
Heptageniidae: C, Sc and R dark, run straight to mid-wing 
then gently curve; Sc and R very close in basal half, then 
diverge; RS with 4 pale main veins (R2, R3, R4, R5), R2 
and R3 branch at basal quarter of wing with 5 intercalaries; 
R4 and R5 branch at mid-wing with one intercalary. M1 
and M2 pale, branch at basal quarter of the wing with one 
intercalary; Cu1 and Cu2 pale and simple, diverge with 
two pairs of intercalaries, the shorter pair adjacent to Cu1; 
A1 pale with 3 intercalaries between A1 and wing margin. 
Cross-veins reduced, pigmented in the Radial and Medial 
fields; arranged in four transverse bands, the basal band not 
contiguous and less distinct. Costal area with 11 cross 
veins, proximal four cross-veins and costal brace strongly 
pigmented in surrounding membrane; pterostigmatic area 
with seven simple, not anastomosed, veins.
Hind-wings with slight costal projection present; Sc 
sigmoidal in basal third diverging from stem of R then 
running parallel to C, gently curving posteriorly; R1 almost 
straight, curved gently at wing-tip; R2 and R3 floating (not 
joined) with one intercalary; R4+R5 branching from R1 
at basal third; R4 and R5 branching almost at distal third 
of wing, with one intercalary; M1 and M2 simple and 
diverge with 2 intercalaries; Cu1 and Cu2 parallel, with two 
intercalaries between M2 and Cu1; A1 short, floating and 
indistinct. The left hind-wing appears to have a colour band 
but this is a taphonomic artefact, not original pigmentation.
Fore-leg (Figure 3): femur 1.8 mm long; tibia 2.2 mm 
long; tarsal claws dissimilar, with one pointed and one blunt 
claw on each leg; 5 tarsal segments, 2 – 4 very long, 1 and 
5 short, segment 1 length 0.2 mm, segments 2 and 3 length 
1.0 mm, segment 4 length 0.8 mm, segment 5 length 0.3 
mm.  Mid-leg: femur 1.6 mm; tibia 1.5 mm; tarsal segments 
difficult to see due to the amber, however they are all very 
short; 2 distinct sharp claws.  Hind-leg femur 1.4 – 1.5 mm; 
tibia 1.4 mm, tarsal segment 1 length 0.1 mm, segments 2 
and 3 length 0.2 mm, end of leg not present.
Forceps base elongated with small spine apically; 
forceps three-segmented, segments 1 and 2 with slight 
projections apically, segment 1 length 0.5 mm, segment 2 
and 3 length 0.1 mm.  Penis lobes sub-quadrate, divergent, 
split to base (Figure 4). Caudal filaments, basal 3 mm of 
left filament present.
Female imago. Length from tip of head to tip of abdomen 
4.9 mm. Fore-wing length 6.2 mm, width 2.1 mm; hind-wing 
curled so not possible to measure.  
Abdomen length 2.8 mm, broad, with the remains of 
some eggs. 
Fore-wing venation similar to male except one extra 
cross-vein in pterostigmatic area and an extra ‘band’ of 
cross-veins at wing-tip.
Legs at angles that make measurement difficult.  Fore-
leg tarsi with segments 1 and 5 shorter  than 2 - 4. All three 
legs have dissimilar claws with one pointed, one blunt.
Length of caudal filaments – 13.6mm, annulated, but 
flattened for much of the length.
Male and female subimagos and nymphs are unknown.
In the same piece of amber is a fulgoroid bug (Hemiptera: 
Fulgoroidea), spider (Arachnida: Araneae), 2 male and female 
chironomid midges (Diptera: Chironomidae), 2 parasitic 
Maccaffertium annae sp. nov. (Ephemeroptera: Heptageniidae) from Mexican Amber (Miocene) 3
Figure 1. Overview of the Mexican amber piece NMS G.2008.34.3 showing inclusions- bottom left, male imago holotype of Maccaffertium annae sp. 
nov.; top right female imago paratype, partially overlain by a fulgoroid bug.
Figure 2. Right wings of male imago holotype of Maccaffertium annae sp. nov.
Macadam and Ross4
Figure 3. Dorsal view of genitalia of male imago holotype of Maccaffertium annae sp. nov.
Figure 4. Right fore-leg of male imago holotype of Maccaffertium annae sp. nov.
Maccaffertium annae sp. nov. (Ephemeroptera: Heptageniidae) from Mexican Amber (Miocene) 5
wasps (Hymenoptera: Parasitica, incl. Chalcidoidea), male 
coccoid (Hemiptera: Coccoidea) and wing tips and legs of 
a caddisfly (Trichoptera).
3. Discussion
Over 150 extant species of mayfly are known from 
Mexico (Mayfly Central, 2014, www.entm.purdue.edu/
mayfly [accessed 15th October 2014]).  The Heptageniidae 
are represented by 12 species, however Maccaffertium 
annae sp. n. is the first fossil Heptageniidae species recorded 
from Mexican amber.  
The genus Maccaffertium comprises 19 species. 
Maccaffertium annae sp. n. can be distinguished from other 
known species of the genus by the following combination of 
characters: fore-wing cross-veins reduced, pigmented in the 
Radial and Medial fields; arranged in four transverse bands; 
penis lobes sub-quadrate, divergent, split to base.  The penes 
and fore-wing venation of M. annae superficially resemble 
those of the type species Maccaffertium mexicanum (Ulmer, 
1920) (figured as Stenonema integrum) in Bednarik and 
McCafferty (1979). The penes are however more slender 
and elongated and the fore-wing venation is greatly reduced, 
much more so than M. mexicanum.
Bednarik and McCafferty (1979) suggest that the genus 
Maccaffertium originated in the Appalachian Mountains of 
eastern North America. They further suggest that the genus 
dates from the Pleistocene era. Maccaffertium mexicanum 
(Ulmer, 1920) is the only member of the genus known from 
Mexico. Two sub-species of M. mexicanum are recognised: 
M. mexicanum mexicanum (Ulmer, 1920) and M. mexicanum 
integrum (McDunnough, 1924), both of which are known 
from Mexico. Bednarik and McCafferty (1979) suggest 
that these populations originated from eastern Texas stock 
however the discovery of M. annae from Miocene deposits 
in southern Mexico disproves this theory.
The male and female imagos in one piece of amber 
indicate that the particular tree that produced this blob of 
resin was probably growing close to a running water-source 
where the mayflies were swarming. Both imagos have 
their wings outstretched indicating that they were flying 
when they became stuck. It is tempting to suggest that the 
individuals were mating, or had recently mated, in which 
case the abdomen of the female would still be filled with 
eggs, however as only some eggs are present this suggests 
she had already laid some before getting trapped.
Acknowledgements
Many thanks to Bill Crighton (NMS volunteer) for 
taking the photographs and Noelia Collado Salas for 
assistance with Spanish translation.
References
Bednarik, A.F., McCafferty, W.P., 1979, Biosystematic revision of the genus 
Stenonema (Ephemeroptera: Heptageniidae): Canadian Bulletin of 
Fisheries and Aquatic Sciences, 201, 1-73.
Elliott, J.M., Humpesch, U.H., 1983, A Key to the Adults of the British 
Ephemeroptera with notes on their ecology,  Scientific Publication 
No. 47, Freshwater Biological Association, 1-101.
Solórzano-Kraemer, M.M., 2010, Mexican amber, in Penney, D. (ed.), 
Biodiversity of fossils in amber from the major world deposits, Siri 
Scientific Press, Rochdale, 42-56.
Manuscript received: October 10, 2014
Corrected manuscript received: February 20, 2015
Manuscript accepted: February 27, 2015


A new species of Mayfly, Maccaffertium annae sp. n. (Ephemeroptera: Heptageniidae) from Mexican Amber (Miocene)

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