The Early Cretaceous Mesofossil Flora Of Catefica, Portugal: Angiosperms
Author
Friis, Else Marie
Author
Crane, Peter R.
Author
Pedersen, Kaj Raunsgaard
Author
Mendes, Mário Miguel
Author
Kvaček, Jiří
text
Fossil Imprint
2022
2022-12-20
78
2
341
424
http://dx.doi.org/10.37520/fi.2022.016
journal article
10.37520/fi.2022.016
2533-4069
7522801
Canrightiopsis crassitesta
E.M.FRIIS, G.W.GRIMM, M.M.MENDES et K.R.PEDERSEN, 2015
Text-fig. 6a–c, g, h
D e s c r i p t i o n a n d r e m a r k s.
Canrightiopsis crassitesta
was established based on fruits, seeds and adhering pollen from the Catefica mesofossil flora (
Friis et al. 2015a
). The fruits are elliptical to spherical in outline and are interpreted as berries with a single seed (
Text-fig. 6a, b
). They are derived from bisexual flowers and remains of a hypanthium, as well as scars from stamens, are present on the probable abaxial face of the fruit, about one third to two thirds of the distance from the base (
Text-fig. 6a, d
). The seeds are orthotropous, pendent and endotestal with a distinct, thick and finely crystalliferous endotesta (Textfig. 6b, c). The outer surface of endotesta is characterized by relatively large pits arranged in longitudinal rows that are also visible where the fruit wall is compressed or poorly preserved (
Text-fig. 6a
). The tegmen is three cell layers thick. In some specimens, remains of an endothelium are seen as slightly elongated cells, but the distinct endothelium seen in other species of
Canrightiopsis
has not been observed. Pollen grains attached to the fruits are similar to dispersed pollen assigned to the extinct pollen genus
Clavatipollenites
COUPER
(
Text-fig.
6g
, h
). Grains are 12–14 µm in equatorial diameter, monocolpate, semitectate-reticulate with a long, extended colpus with an irregular margin. The reticulum is composed of narrow, beaded muri supported by long, scattered columellae (
Text-fig.
6g
, h
). The embryo is minute and surrounded by a nutritive tissue of thin-walled, isodiametric cells (
Text-fig. 6b, c
).
A f f i n i t y a n d o t h e r o c c u r r e n c e s. Analysis of the phylogenetic relationships of
Canrightiopsis
placed the genus in the
Chloranthaceae
as part of the
Ascarina
J.R.FORST. et G.FORST.
-
Sarcandra
GARDNER-
Chloranthus
SW.
clade, particularly close to
Sarcandra
and
Chloranthus
(
Friis et al. 2015a
)
, a result also supported by a subsequent analysis (
Doyle and Endress 2018
).
Fruits and seeds of
Canrightiopsis
are common in Early Cretaceous mesofossil floras from
Portugal
. In addition to
C
.
crassitesta
, two other species have been recognized including
C
.
intermedia
and
C
.
dinisii
E.M.FRIIS, G.W.GRIMM, M.M.MENDES et K.R.PEDERSEN. Only
C
.
crassitesta
and
C
.
intermedia
are present in the Catefica mesofossil flora.
C
.
crassitesta
is distinguished from
C
.
intermedia
by its much thicker endotesta, but the two species are similar in fruit morphology and without internal details, the fossils are difficult to separate. All
Canrightiopsis
specimens from Catefica studied using SEM are typical
C
.
crassitesta
, while only
one specimen
is a distinct
C
.
intermedia
. Other specimens from Catefica for which internal features are unknown are referred to as
Canrightiopsis
sp.
(
Friis et al. 2015a
).
Fruits and seeds of
Canrightiopsis
are particularly common in the mesofossil flora from Famalicão, but are also reported from the Arazede, Buarcos, Chicalhão,
Vale
de Água and Vila Verde mesofossil floras (
Friis et al. 2015a
). Currently
C
.
crassitesta
is reported only from the Catefica mesofossil flora.
Pollen grains found on fruits of
Canrightiopsis crassitesta
are similar in size and general morphology to those found in situ in isolated stamens and inflorescence fragments from Catefica with
Clavatipollenites
-type pollen (
Text-figs 10– 13
,
Tab. 1
), but the reticulum of the pollen associated with
xy1485) through fruit in the region of the hypanthium rim showing sections through the two seeds close to the chalazal region; note endotesta (oi-end) surrounded by larger cells of exotesta (oi-o) and fruit wall (fr). Specimen, Catefica 49-S174249 (
holotype
, a–f). Scale bars = 300 Μm (a–c, e, f), 100 Μm (d).
Text-fig. 4. Synchrotron radiation X-ray tomographic microscopy (SRXTM) images of seeds of
Canrightia foveolata
sp. nov.
; Catefica locality, Portugal. a–d) Volume renderings of abraded seeds in ventral (a), lateral (b, d) and apical (c) views showing the slightly protruding chalaza (arrows) and dense longitudinal grooves with shallow pits in the surface of the endotesta; e) Transverse section of seed (orthoslice xy0665) showing the irregular grooved surface of the endotesta (oi-en) and the tegmen comprised of two layers of thick-walled cells that surround the cells of the prominent endothelium (asterisk); f) Longitudinal section (orthoslice xz1195) through seed showing the thin-walled endothelium cells (asterisk) surrounded by the thicker cells of the outer tegmen and endotesta; g) Longitudinal section (orthoslice yz0727) through seed showing outlines of angular crystals evenly distributed in cells of the endotesta (oi-en); note the outer epidermis of the tegmen (ii-o) composed of thick-walled cells; h) Longitudinal section (orthoslice xz0940) of seed showing details of the chalazal region with course of the vascular bundle (vb), cells of the prominent endothelium (asterisk), crystalliferous endotesta of the outer integument (oi-en) and the distinct thick walled cells of the outer cells of the tegmen (ii-o); i) Longitudinal and tangential section (orthoslice yz0542) through the endotesta (oi-en) showing the outlines of densely spaced crystals. Specimens, Catefica 242-S175178 (a–c, e–h), Catefica 49-S175179 (d, i). Scale bars = 300 Μm (a–d), 100 Μm (e, f, h, i), 50 Μm (g).
Text-fig. 5. Scanning electron microscope images of the seed of
Canrightia
sp.
; Catefica locality, Portugal. a) Seed in ventral view showing the slightly protruding chalaza (ch) at the apex, pointed micropyle (mi) at the base and pitted surface of the endotesta; b) Detail of endotesta surface showing larger pits in longitudinal rows and the finer pits created by crystals in the cells of the endotesta. Specimen, Catefica MM158-P0289 (a, b). Scale bars = 300 Μm (a), 100 Μm (b).
Canrightiopsis crassitesta
is more open and the grains are smaller.