THE GENUS LIGERIMYS (RODENTIA; EOMYIDAE) FROM THE RIBESALBES-ALCORA BASIN (EARLY MIOCENE, SPAIN)

1. THE GENUS LIGERIMYS (RODENTIA;
EOMYIDAE) FROM THE RIBESALBES-
ALCORA BASIN (EARLY MIOCENE, SPAIN)
V.D. Crespo1,2,3* , A. Gamonal2, R. Marquina-Blasco3,4, and P. Montoya4
1 División Paleontología Vertebrados, Museo de La Plata (UNLP) and CONICET, La Plata, Argentina
2Museo Paleontológico de Alpuente, Alpuente, Spain
3Museu Valencià D’Història Natural, Alginet, Spain
4Palaeontology of Cenozoic Vertebrates Research Group (PVC-GIUV). Department of Botany and Geology, University of Valencia, Burjassot, Spain
*vidacres@gmail.com

2. What is an eomyid?
Eomyids are an extinct family of rodents found throughout much
of the European Cenozoic, probably of Asian origin. The record in
Europe begins in the early Eocene and extends into the Pliocene,
with a maximum of diversity between the late Oligocene and early
Miocene.
Eomyids were generally small, but occasionally large, and
tended to be squirrel-like in form and habits. The family
includes the earliest known gliding rodent, Eomys quercyi.
Figure from Kimura et al. (2020). Diversity of eomyid rodents in North America, Europe, and Asia, counted as “range-through” occurrences of eomyid genera. Two
datasets were used to generate the diversity curves. All taxa were included in one dataset (solid line), and in the other dataset (dashed line), singleton taxa, were
removed (any genera whose first and last occurrences are restricted to a single time bin; Sepkoski 1996). In each time bin, a data point is placed in its median age.

3. Geographic context: the Ribesalbes-Alcora Basin
Distribution of Cenozoic basins (yellow) in Spain.

4. Mas d’Antolino outcrop
Geographic and geological setting of the Ribesalbes-Alcora Basin, showing the location of the outcrops of the Campisano ravine.
Modified from Crespo et al. (2018). MCX: Mas dels Coixos; MTR: Mas de Torner; ACS: Araia Cantera Sur; BC: Barranc de
Campisano; FS: Foieta la Sarra; MAB: Mas d’Antolino B; CBR: Corral de Brisca.

5. Syntethic column
Figure from Crespo et al 2019. Detailed
lithostratigraphic columns of the Corral de Brisca
(CBR), Mas d’Antolino B (MAB), Foieta la Sarra
(FS), Araia Cantera Sud (ACS), Mas dels Coixos
(MCX) and Mas de Torner (MTR) sections from the
Campisano ravine (Ribesalbes-Alcora Basin). The
scale is in metres (synthetic column, Mas de Torner,
Araia Cantera Sud, Foieta la Sarra and Mas
d’Antolino B columns) or centimetres (Mas de
Torner 1 (MTR1), Corral de Brisca and Corral de
Brisca 0 columns)
The faunal assemblages of the
levels indicate an early Aragonian
age (MN4, early Miocene) which
has been inferred from the
presence of rodent taxa such as
Megacricetodon, Democricetodon
and Ligerimys. This rodent
assemblage has allowed us more
precisely place these sites to the
local biozone C of the Calatayud-
Montalbán Basin (Spain).

6. Ligerimys florancei
Figures from Crespo et al. (2021). Teeth of Ligerimys florancei from the Ribesalbes-Alcora Basin. A- dp4; B-C p4; D-E m1/2; F- m3;
G-H DP4; I-J P4; K-L M1; M-N M2; O- M3.
It differs from the L. ellipticus in that it is
larger in size and has a rhomboidal shape
of the ridges on the lower molars.

7. Ligerimys ellipticus
Figure from Crespo et al. (2021). Lower
teeth of Ligerimys ellipticus from the
Ribesalbes- Alcora Basin. A-C- dp4; D-
H p4; I-S m1/2; T-Y m3.
It differs from L. florancei by its smaller size, and its
circular shape on the lower molar ridges. It also has
a lingual anterolophid of variable shape and
presence, but always reduced, being the most
frequent labial one.

8. Ligerimys ellipticus
It differs from L. florancei by its smaller size. It also has a
primitive labial mesoloph is present in low frequency and, in
less common, in the central part
Figure from Crespo et al. (2021). Upper teeth of Ligerimys
ellipticus from the Ribesalbes- Alcora Basin. A-F DP4; G-L P4;
M-S M1; T-A’ M2; B’-I’ M3.

9. Biostratigraphy
Depending on the species of Ligerimys present, we
have been able to divide the record of the
Campisano Ravine section into two long local
biozones, an older one with the presence of L.
florancei and a more modern one with L. ellipticus.
In addition, each local biozone is divided into two
smaller sub-biozones, depending on the
abundance of each species
Figure from Crespo et al.
(2021). Composite
column of the Campisano
Ravine with positions of
the studied sites and the
different local biozones
and subbiozones present
in this section. MCX: Mas
dels Coixos; MTR: Mas
de Torner; ACS: Araia
Cantera Sud; BC:
Barranc de Campisano;
FS: Foieta la Sarra; MAB:
Mas d’Antolino B; CBR:
Corral de Brisca.

10. Biostratigraphy
We compare and correlate the
assemblages studied here with
other Ligerimys assemblages from
the other basins in the Iberian
Peninsula and classify these sites
based on the abundance and
species of the genus Ligerimys.
Figure from Crespo et al. (2021). Relative abundance of the genus Ligerimys as compared to the rest of the rodents in the most representative sites of the
Iberian Peninsula, together with the main sites studied in this publication. a: Biozone L. palomae with more than 5% of abundance. b: Biozone L. florancei
with more than 5% of abundance; c: Biozone L. florancei with less than 5% or without presence of the genus; d: Subzone L. florancei with more than 5% of
abundance; e: Biozone with presence of L. florancei and L. ellipticus. f: Biozone L. ellipticus, with more than 20% of abundance; g: Biozone L. ellipticus,
with less than 20% of abundance; h: Biozone L. ellipticus with less than 1% of abundance. SR: San Roque; OR: Olmo Redondo; VL: Villafeliche; ART: Artesilla;
MCX: Mas dels Coixos; MTR: Mas de Torner; BC: Barranc de Campisano; MAB: Mas d’Antolino B; Bar. Cand.: Barranco de Candel; CMV: Can Martí Vell;
CDLV: Les Cases de la Valenciana; BÑ: Buñol; VR: Vargas; FS: Foieta la Sarra; Mon2: Montalvos 2; CBR: Corral de Brisca; MT1: Morteral 1; LCA: La Col A.

11. Thank you very
much for your
attention!!!